You can add an Avatar and a Signature by going to the Profile tab and clicking the appropriate option.
I do require an Avatar of all my players, and an appropriate one at that.
I also prefer your username to be your character's name for simplicity sake.
For spellcasters, I recommend using the Signature option to list off your prepares spells and spell slots. Like the example below.
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Prepared Spells:
Magic Missile
Shield
Spell Slots:
Level 1: OOO