A description is one of the most important parts of your character. It's the part that other characters see of you, and it provides all the knowledge they have about you. It also provides a great deal of information to other players. If your description is badly spelled or written, they may think less of your RPing ability, no matter how unfair that seems.
In order to help you make a description, we've listed things you should and shouldn't include below. If you do most of the dos, and don't do any of the don'ts, you'll be fine.
Don't feel you need to write only what's on the do list. Add anything else you think appropriate, such as the pitch of voice, the way the character moves (lumbering, graceful, etc) or even the smell that hangs in the air around your character. For courtesy's sake, please keep your description to under a page. This also helps you out, because people will read it and not just skim through it as spam!
-Height. (Either saying 5'6" tall or of average height will do)
-Build (Lean, rounded, or about 255 lbs.)
-Sex (him or her) See our gender policy.
-Hair, colour and length, if any.
-Fur/skin colour and texture, if non-standard.
-Eyes, colour and shape.
-Actions (she smiles or he waves)
-Value judgements (a handsome jaguar or the prettiest feline you've seen)
-Forced thoughts/actions on the viewer (you feel scared of his deep gaze or you can't keep your eyes off her breasts)
-Anything someone couldn't know by looking at you (very intelligent or hates evil)