Very interesting question...
If I can offer you a little piece of advice, the best characters you can write are the ones you can relate to. Not exactly feel identifed with, but characters that connect with your world and that, therefore, you can know well.
For example, when I write my scripts, I try to project people that I know very well into these imaginary characters. Like my parents, an old friend, or even yourself... That way you can add an interesting personality to the character that it's difficult to find if you try to invent it from scratch.
Something good that you can try is to look at existing characters that you admire or relate to. Personally, I tend to identify with Peter Sellers' character from Being There, and admire Quint from Jaws. From those two, I can write my own set of characters with similar personalities or even totally different ones! The clue is to make them interesting, complex and three-dimensional. It's not easy, but once you're able to write your own set of characters, the story can progress along very nicely.
I know I didn't answer your question very well, but if it helps, Mrs Brisby is designed to look "cutesy" because her personality demands so: She's scared, and she's very fragile. But she has to overcome her own fears to save the life of his kid.
Sometimes you'll think of how the character looks first and then how he behaves, or the other way around... It doesn't matter, really. Try to start by having fun!
Sorry for the long post!
Do you have any examples of your characters? Looking at something a little different might shed light on the visual aspect...
Well yes, I have an example of a short I just wrapped filming last week. Take a look at this guy...
This is a character I created. He's an old gaucho who's returning to the land he used to belong... Now what's he like? He's a legend, he's like a living ghost. Wherever he goes people watch him like he's an apparition and everyone respects him, because he used to be a hero.
But now he's old and his own land is nothing like he remembered; the places he used to remember are destroyed or don't even exist, and most of his friends are gone. He's just returned for a last act of valor before dying.
That (at least for me) is an interesting character because he can be ambiguous. Everyone talks about him like the hero he was, but he's not a hero anymore. He's just an old man who wants to die.
You can try that too: Making your character ambiguous. Not good or bad, but in between that very thin grey line... For example, Silver from Treasure Island is a fantastic character because you never know if he's going to kill you or help you... Of course, he's like that because he's the main villain, but you can make most of your characters have double intentions, and that way a very simple plot can end up being complex because of your characters!
I hope that helped, even if it was just a little
If you want, share with us your characters and maybe with our combined strengths we can rule the galaxy! I mean... Help you in any way we can :P
For right now, I'll show you my complex characters. They are described in a short novel I wrote (not published yet.) It's based on Norse/Celtic mythology. I am working on bringing all of the sword and sorcery myths back to their original roots as opposed to using that Dungeons and Dragons styled stereotypical orcs n' elves stuff.
COORWIN OF GLENSHIRE (Human)-Young, arrogant, rash, empathetic, and experienced. He has wind-blown red hair, a chiseled face, a muscular build, and dresses in cracked leather and cotton garments. His origins are a mystery, but he enjoys his life in Glenshire, seporated from civilization until a chance meeting with a druid on the borders of Albia. He carries a longsword forged by the first humans of Asgard. His sword has a golden guard with a blue gem.
WOLF OF HRON (Human)-Young, arrogant, seasoned, cold, calculated, collected. As a child, he was scorned for being the inferior offspring of mixed Norse and Gaelic origins. Forced to give up is dreams of the huntsman, he has lived in exile. Neither clan in the North nor Albia accepts him due to their hatred for one another. He is a skilled thief, a superior archer, and a dangerous swordsman. He is physically taller than most humans, and has a scar on his cheek from the duel in which he killed his gaelic father. He is a foil to Coorwin most often, but manages to maintain a place as Coorwin's best friend in his journeys. He has a very Brutus and Cassius styled relationship to Coorwin, and is understood only by Coorwin and Sul' Calmuru. (Coorwin revering him as a friend, and Sul' Calmuru acting as a mentor.)
SUL' CALMURU OF ALBIA (Half-giant. Also called Albians due to their residence in the isles of Albia)- Difficult to decipher an age because of his immortality and his odd features. He is eight and a half feet tall. He carries a bow that is slightly taller than he is, and wields two long-swords which are modeled after the celtic crescent guarded swords used by my own clan in the middle ages. (He is a bit of a personification of my ancient Irish ancestor mixed with me). His hair is grizzled jet black and grown to his shoulders. He dresses in animal furs, a curious looking cuirass adorned with knot-work (Armor worn about the torso), and wears a long green cloak with golden trim. He is wise, as he has been on earth since creation, and is the last of his race. Numb to war after having fought for ages, he is conflicted with sadness (as he can no longer pride himself with his long dead clan), and developes riddles to end battles before they begin. He is well known for his scorning of the Vikings and the Geals in their first war. During the first battle, he gave the vikings' leader a chance to walk away. He calculated a shot, and fired straight above into the air. As the arrow ascended from all sight, he declared that it would strike the one who put his evil ways aside lastly. When the viking refused to end the battle, the arrow pierced his helmet upon descent, and officially ended the battle.
ODA THE WISE (My name translated into Gealic. Meaning Wise one, Cushion, Helper) Oda more commonly known as the shadow of Odin, is a wizard as old as Sul' Calmuru, and by far wiser. He is the head of the shadows, an order of god-like beings directly opposite of the gods who seek to free man of the petty gods of Yggdrasil (Tree of the God's from which Odin hanged in self sacrofice in mythology. It is a great Ash tree growing in the ocean, reffered to in norse mythology as "Gununngagap) He manipulates man to work against the gods when he sees that man has been fed up with a god. He dresses in elaborate crimson robes adorned with various animal products. He is essentially a druid, following the philosophy or Oran'Mor (Celtic story of eternal creation through which no gods actively create the world, but are simply beings of heightened intelligence and power, and defeatable by mortal blades.) Oda tends to be the dark fellow who's intentions are never disclosed. he is a blank slate when compared to other characters, meking him an utter mystery.
KELLI OF DWELINDOR (Dwarrow "Dwarf" when translated from Germanic norse) His name is an ode, again, to my clan. I am an O'Kenny, a sect of the O'Kelly clan, once called Killi. He is hot tempered, humored, funny, (more often used as comic relief than for serious debuts) His height is often used to humor the reader. For example, when the company of characters are moving with a caravan and all of the normal sized people ride in the seats, and KELLI rides on top, while SUL'CALMURU walks along.
"Why am I always on top!?" Said Kelli,
-"Cause you're the shortest!" Chuckled Boru.
-"I don't even get to ride the damned thing!" exclaimed Calmuru.
Each chuckled a tickle of friendly humor, and rode into the next day...
He is short, ebon bearded, and carries a battle-axe, and a sword (Traditionally depicted weapons of dwarves in Norse mythology)
VOLONDIR (VOL-UN-DEER) King of the Alfar (Elves when translated from Norse to English) he is an ever wise friend of Oda's and Calmuru's. His people have a heavy influence of the Gaels of Albia(Albia being an old English deviant of Albiaon, the name given to the Celtic regions of western europe in the iron age. He is known for his peaceful ways, and Calmuru and he have basically the same views on armed combat. Either end it before it begins with a riddle, or somehow eliminate the agressor's leader. Unlike the elves of high fantacy, VOLONDIR does not expressively use a bow and arrows. He did teach Calmuru how to use his, and even had his people carve Calmuru's bow out of the sacred Yew tree. He is dedicated to his role as father of the elves, and collaborates closely with the lady of the yew.
BORU (human) Rash, young, arrogant, angry, socially mute, and vengeful. He keeps a snear on his face and a single braid in his short blonde hair. He dresses in a green kilt and cracked leather garments, carrying a sword won from a viking during his first battle. He is known for fantastic acts of ferocity.
MAR (middle-eastern human) He is the soul living being to have crossed the great teeth (A jaggad mountain range that splits west and east in half). He is humble, carries a scimitar, and has learned all the languages of the realm. He claims to be a prince of his realm, and according to him, his civilization is rebuilding after a tidal flood from beyond the sea. He dreams of connecting west and east, and bringing the life of the west to the deserts. he wields a basket hilted sword, and a divice similar to a 1200ds styled pistol, which he claims to have obtained from his eastern allies, whom he describes as peculiar in thier dedication to their mortal emperor.
PRINCE TARIUS OF HRON (human) Humble, Just, Empathetic, Authorative Fanatical. Tarius is the lost prince of Hron. in recent years, the prince has dissapeared in the east, just near the great teeth. Three months after his disappearance king Turentius was struck down by a masked swordsman who's sword, as opposed to sundering him, completely froze him too his throne. The swordsman bore "Two voices". He is actually Tarius himself, however Tarius is posessed by a demonic presence as one would find out in reading, and acts very similarly to an extreme schizophrenic. He acts as two characters. The presence inside of him reveals himself as Asher.
ASHER, SHADOW OF LOKI. Calculated, Vengeful, Fanatical, Lacking empathy, a foil to Tarius in every way. Asher is the only shadow to seek refuge in the old gods, particularly his counterpart, Loki. Asher is obsessed with two conflicting elements, fire and ice. He has a supreme understamding of both, and has found ways to manipulate matter to create these elements.
(I can go on, but this story has litterally thousands of characters.)
I'll show you guys some of my animal characters. I can take a human as complex as complex goes. Animals are where I have trouble.
I really like what I'm reading! Your characters seem to be very well defined and even relatable! I specially liked Oda the Wise, because of how ambiguous he could be.
Dammit, now I want to read that novel bad! When is it coming out??
Keep up the good work!
Well, considering my age, no publisher will really take me seriously. The book itself is heavily based upon Viking mythology. I touch a little bit upon Celtic mythology as well. To describe it, I'd say, long, detailed, violent, emotional, and all together, emmersive. I have a friend that has actually engrossed himself in the stories I've created like a World of Warcraft geek. So, I think I'm on the right track. Currently, it's a combination of random short stories that tie in to each other. The setting is a massive world that is completely fictional, and ties into the real world. A prehistoric Europe similar to Robert E. Howard's "Hyborean age". My particular time period is the "Age of Arderon". Arderon itself is similar to Iron age earth. The days of the celts and the norse. When reading it, you'll hear about Giants, elves, dwarves, faeries (Not to be confused with fairies); The usual sword and sorcery stuff. My work is unique in that I rely heavily on the original mythology, and don't use the Dungeons and Dragons stereotypes that have so defined the genra since the seventies. My elves arent tall pointy eared archers, they are very similar to druids. My faeries are shape shifters that guard the forests. The elves are ruled by "Frey", while the Faeries are ruled by "Freya". It would take too long for me to elaborate too much. It's a very vast universe that my stories take place in.