I have tried many different methods of putting labels on clear mount stamps. I was surprised when I stumbled upon a new technique by SU! demonstrator Maureen McGrail, and I actually think it works the best!
1. Start with a new stamp set. Turn the entire piece containing the stamps over to the back and peel off all of the white backing paper.
3. Now find the label you want to start with. Peel the entire sticker, including the paper backing, off of the label sheet.
4. Find the slit in the paper on the label. Peel off one side ONLY.
5. Using the half of the label with the paper still attached, line up the label to the back of the corresponding stamp.
6. Once in place, gently let the sticky side adhere to the stamp. Lightly rub to ensure it is in place.
7. Now remove the other part of the paper and just let the sticker gently roll into place, lightly rubbing to completely adhere.