my better half blanches the skin off, then slices them into 1/8 size slices. Place them on parchment paper on a cookie sheet and then place in freezer at least overnight. Then place the frozen peaches into a freezer bag of the desired size. Doing it this way prevents the peaches from becoming a big clump in the freezer.
She also squeezes a little lemon over them prior to placing on the cookie sheet.