Shorts and/or slacks, depending on the weather.
Sometimes long underwear beneath the slacks.
Years ago I mostly wore slacks, for some reason I played better with slacks vs. shorts.
Probably a mental factor.
Try choking down on the irons an inch or so, stop the backswing when you feel the clubhead is pointing to the sky, then start the downswing with the pulling motion of the left arm, be aggressive (not fast/quick) with...