In order to get more surface area for the barbecue sauce, I like to butterfly my chicken. To do this, simply make a deep cut across the breast, parallel to your cutting board. Cut it almost all the way through, but not quite in half. Then open the pieces up like a book (or butterfly ;)) and press down on the "seam" with your hands so that it lays flat. Butterflying your chicken also means that you get a nice thin piece that will cook up very quickly.