Decide whether you want to lean more towards the 'entertainer' side of things, or if you would prefer to let the music speak for itself. Generally, the 'entertainers' make more dough. Unless you are a phenomenal talent, (and if you really were, you wouldn't be makig your living on the street) you'll probably lean a little towards the former anyway. I have played in many cities across Canada, and have managed to do quite well at it when *between jobs*
Something a lot of street musicians fail to realize is that they are being run off because they are either annoying, or just flat out awful. I'm sure you've all heard someone who really made you cringe. By trying to be considerate, and semi-professional, I have managed to play in places that wouldn't normally let buskers play.

Cheers!