I'm a 38H or so, so I know your pain. In general, I've been Boppy dependent, and use cross cradle with my children, rather than the football. When we're out, I sit on the floor, and I rest the baby on my thigh, with the arm closest to his head sometimes under his head when he's little. I use the opposite hand from the breast I'm using to support that breast.
I know a lot of more endowed women who can't seem to get the cradle position down. When the babies get older, they come up with variations anyhow. My 10 month old likes to stand or sit while he nurses now. It's not the most modest position, but it works.