I recently found this post on Tumblr by Jake Wyatt:

Notes for a Young Character Designer

I figured he had some really good ideas, but one issue I had was that he gave some artist examples but there weren't any images to go along with that.

1) On avoiding symmetry: I think this comes almost naturally to most people, especially if you work traditionally (meaning by hand even if your using a computer. Use a drawing tablet or sketch by hand before using 3D software). Consider most Superhero designs.

Iron Man kind of outshines Cap right here. Feels bad having to admit that.

Your design can be symmetrical. Don't go out of your way to create asymmetry, it's naturally occurring. Your details will create it for you. like the the webbing on Spider-Man's suit or the banding in Ironman's underoos.

What's more important is making your design solid and easy to remember for you at the very least

Genya above has a pretty nice design, but it's kept very simple so the tons of people that have to draw him don't have too many issues. In addition to that, you'll notice that his lapel and ascot are the only things keeping him from being symmetrical. 

A considerably worse picture of him. This toy is a slightly different design that doesn't look as good, but it puts the point across.

2) on Avoiding Concavity: This one is a lot harder to explain so it's much much better to see it. 

So Convexity is when something sticks out like a glass lens or Daffy's eyes 

I cannot guarantee that this is a good enough image to explain this idea. 

So naturally concavity is when things are sucked into the surface like wrinkles into skin or cuts and grooves into a clay pot. So how does this apply to your character designs? Well old fashioned robot designs were really great at this and they contrast really well with newer more angular designs. 

Compare these: 

to these:

If you're having a hard time figuring it out just imagine having to draw these guys a 100 times everyday. Or you could look for video of their fights on youtube and judge their range of motion with your own eyes. I'll provide one of my favorites below.

This applies to human shaped characters too. 

Among other things

3) On Graphic Details and Style: This is everywhere lately You can find a lot of Canadian cartoons made like this where they translate really badly. I won't focus on those though because I feel like this is pretty long winded already. Here are some good old examples.

You can usually find some bad examples from Total Drama, Super Noobs, and other broken glass style cartoons. It might look really particular and maybe easier than something  like Berserk, but the guys that draw like this can still draw really complicated stuff like that when they need to and that's sort of where you want to be. It's all knowing how to use structure to your advantage with this and manipulating it. Most people get it wrong thinking that the characters have to move in a particular way as well but it's not necessary. These graphic characters still move like regular "3D" drawings. 

4) on Studying: This comes personal to anybody, but try to absorb as much from as many different sources as possible. Keep in mind that you need to assess everything with your on eyes because this is a visual medium that you're getting into. Jake Wyatt suggests studying "High Focus Figure Drawing" which I do agree with (I plan to get it once payday rolls around) but if my understanding is correct it's about studying mass which I gathered by myself by imagining every circle I draw as a balloon. It's relative though, I learned this buy myself but it took me eight years to figure out how to do it on my own so make it easier on yourself and get some guidance!

Learn to color like a professional Manga Artist

I just wanted to point out how great these covers look to me.

These first two covers are from something called "Nanka Youkai!?" It's about something like a spirit detective couple. I only found out about it a short while ago. It's written by Satomi Kei who also wrote the second group of covers.

These two are my favorites

These come from "Smile for Mii." Google just brings up those awful Nintendo Avatars, so I can't find any information about it.
These types of colors are great. They feel really natural. You only get these by knowing how to neutralize the colors so that they don't overwhelm the simple folks like me.

These last two are completely different in thought but the colors are still pretty great. Not as well thought out though.