The avatars are inexact, so once you have some idea what your character will look like, even if you haven't assembled all of the costume, you can make an appropriate avatar. Then, when you meet folks in-game and connect with them online, they can match the character they saw in-game with your avatar. I for one like visual aids that help me connect names, faces, characters, and costumes together. It's all quite a lot to take in, even with help!
It could also be helpful to add your real first name to your signature, if you're comfortable doing that.