I stand 6'4" with a lean athletic build, and I wear the item before I evaluate it. Every review records the size I wore, inseam, sleeve, torso, and shoulder fit.
I focus on mid-priced menswear between $30 and $100, from brands like Uniqlo, J.Crew, Banana Republic, Levi's, and ASOS Tall. I check fit after washing too, since shrinkage changes length.