I usually wear jeans with an undershirt, the suspenders over the undershirt and then a buttoned or collared shirt over them for work.

My first pair of suspenders were Carhartt and were the one size fits all. They were about 3 inches too short for me. I'm 5"10' with a 52 waist size jean.

These Levi's are great! The clasps end up about chest level, so I have plenty of room to spare, but also they don't show up under my outer work shirt the way the Carhartt did.