The fall 2009, issue #36, Scrollsaw Woodworking and Crafts Magazine, has full step by step instructions for making a Scarecrow Intarsia; It has suspenders that attach to his pants. It would work just as well for attaching suspenders to waders.
It's a Judy Gale Roberts pattern, but I don't see the pattern listed in her "Intarsia Times" probably because it was a free pattern in the magazine. She does have a matching girl scarecrow listed.