I've found the most challenging part of shortening armor (I'm short too) is in the thighs. Some people like to just hack around the bottom part, around the knees, and be done with it. I think this takes away from the overall look of what is supposed to be there. I like to keep the all the detail there & just trim the upper part instead. You just have to be careful to keep them in the right proportions around the top of your leg.
For the lower legs, I trimmed just a bit off around the ankles. They didn't need much. With most of the accurate sized aromr makes, you won't have to really trim much, but if you want to be able to walk around comfortably at all, you'll need at least some trimming.