I agree with the one who says get new sweaters. Especially chunky ones. Tucking them in can make you look fat, as well as short. Sweater come with a finished appearance for a reason.
I agree with GQ, tucking in a sweater is a high-degree-of-difficulty style move. But still, it's worth the try..
Margaret Howell Fall/Winter 16 was like a non-stop sweater tuck.