The Blank Slate
Don't have a clear character concept in mind? Is the game already started? Just use the Blank Slate method of character creation. Put a blank piece of paper in front of you. This is your character sheet. Try to think of your character (just description, personality, etc.). Try to come up with a quick intro...what would someone think about the character at first glance. You're ready to play Risus. You're going along, listening to the GM, when a situation comes up that requires a roll of the dice. What do you do? Simple, you come up with a cliché for your character right there on the spot that seems to fit. You can give this cliché any rank you want (up to the max). Just write it down on your character sheet. Keep doing this until all of your dice/points are used up. You'll have a complete character in no time.
Feel free to combine this method with regular Risus character generation (i.e. you don't have to spend all of your dice/points during character creation).