Water balloons! In 40 years I've only had two "leak". By carefully tying them twice I make perfect nipples and can adjust the size of my breasts as desired by filling them as much or little as I want. The feel and weight is wonderful.
I just found a new Just My Size "gel Strap" in size 44DDD. It is a little smaller cut than some but I enjoy it very much.
Works fine for me . . .