wide pants are the obvious thing. jeans, chinos, fatigues, double knees, whatever. I'm also a fan of Needles' big track pants.
A big shirt can certainly work, but try big, high rise pants, with a small shirt / tee / sweater tucked in, and then layer a big coat over that that's on the longer side — a chunky bomber, a thrifted overcoat, whatever you're into. the long coat + high rise pant creates two different horizontal lines, so you get the proportion benefits of both—your legs look long but your torso doesn't look short.
then, you can go in a lot of different directions with the shoes. hiker-sneakers, chunky loafers, funky boots, weird mules, paraboot michaels, those 3sixteen sidezips, anything from yuketen...
