All Amish men wear suspenders. A belt is a worldly thing.
Why Not a Belt
Belt with buckle — ornamentation (vanity). Suspenders — function. Amish suspenders: black or dark blue, no patterns, no brand. Nothing decorative.
Advantages
Don't press the stomach (important for bending work). Pants stay up when raising arms (lifting bales, building). Distribute weight on shoulders, not waist. More comfortable for physical work.
Making
Two strips of elastic webbing (2-3 cm wide). Cross on the back (X-shape). Attach to pants with buttons. Adjustable length. Cost: $2-5 from fabric and hardware.
Fact
Young unmarried Amish wear one suspender strap. Married — two. You can tell marital status by suspenders.