I'm short too but I've found that either long coats (+boots helps here) or short cropped jackets can work well. Anything in that middle-length range seems to make me look shorter. Looking short or tall is all about unbroken vertical lines. Either the whole line of your leg (cropped) or the line of the long coat (chesterfield). If you have comparatively long legs the former is slightly better, but if you have stumpier legs, the latter is better.