Here is a sanding tip from @jewelryinstructor - “Here’s a quick tip from my bench to yours: when you need to make sure the bottom of a form or frame is completely flat, color the edge thoroughly with Sharpie marker. Gently drag the piece across sandpaper in two directions and check it - any remaining marker will show you where the low spots are.” Thank you so much Francesca! Francesca is a jewelry instructor and even has an online class available for beginners, check the link in her profile! We appreciate you!