After pinned, measure from hem to fold. In this picture, my measurement is 3 3/4″. That means that I need to hem up the pants 3 3/4″. Next, unpick the hem. Mark the amount up from the hem-line. (If you look closely, you can see two white marks on either side of pants.) Use a ruler to mark a straight line across on the marks. Mark 3″ down from the new hem-line. This is the cut line. Cut on the cut line.
Fold the bottom edge over 1/2″ and iron. Do this to the whole bottom edge to finish the edge.Fold the pants up at the hem-line and pin.
Hand-hem with a vertical stitch. Here’s a great diagram to show the stitch I’m doing. The finished hem. With this stitch, you can’t even see any stitching!