Hi Rick,
You look em in the eye, performance notes are right on the money. I was very surprised, years ago, when I went from busking on the war pipes to the Uilleann pipes, and there was a drop off of money. I got to doing some serrious thinking about how people were reacting to me. I was useing a low stool (for the unfamilier, you have to sit down to play the Uilleann pipes). Folks were looking at the crouching figure, and it reinforced their "Bum" notion of the busker, no matter how good the playing was. I noticed folks would kind of become aware of the music after trying to ignore me. So, I began to carry a bar stool, a real bitch to carry, but it brought me up to eye level. The attitude and money changed at once. Funny. Presentation is everything.
Larry