This is probably the stupidest thing to do a post about, but I have always been a little perplexed about how to perfectly fill an oval or circular locket. It's hard to just randomly cut out an oval and hope it fits, and the edges always end up looking jagged and messy. So now that I figured out how, I thought I'd share it in case anyone else was equally baffled :)
1. Measure the locket's height and width.
2. Create a new photoshop document with the same height and width. (My adorable Hypatia desktop background kind of looks creepy in this photo lol)
3. Create an ellipse shape that fills your document. That shape is now the size of your locket!
4. Open the image that you want in the locket. Copy it, and paste it into the document. Create a clipping mask (right click on the image layer and select "create clipping mask.") so that the image now takes on the shape of the ellipse.
5. Print it out! I have a Xyron sticker machine that can make anything into a sticker, so I usually run my image through that, cut it out and pop it in the locket. But you could also print it on sticker paper from Staples or go the old fashioned route and use a glue stick ;)