What's the best way to play with my breasts

Have a friend lick and play with them for you. Alternatively, get them nice and soapy in the shower or covered in baby oil and rub them and squeeze the nipples between your fingers. However I recommend a combination of the first suggestion and the second.
I suspect if you have a friend naked in the shower with you playing with your breasts you may not stop there ;)

Having someone else work on them should be the best, there's nothing like someone else's touch especially if it's someone of whatever sex turns you on.