How would I make an earring/jewelry holder?

You can use an old key rack or picture frame. Here's one I made:

https://www.hometalk.com/diy/bedroom/organizing/key-rack-turned-jewelry-organizer-8219389

Buy a standard wood picture frame in the size you want , remove the glass and backing and staple window screen to the back. You can get rolls of screen at Lowes or any home improvement store. You can also use chicken wire but that doesn't works as well for studded earrings.

Here’s some great instructions: https://www.hometalk.com/diy/bedroom/organizing/upcycling-old-picture-frames-into-jewellery-holders-11479093

Hello. Assembling your materials might be a personal choice. Choosing your type of style frame that you prefer spray painting that. Then cutting the metal mesh or decorative grill to insert into the frame would follow. Insert hanging hooks on the back. That’s how I would consider making my project.

More ideas here

https://www.hometalk.com/search/posts?filter=earring%20holder

I would buy an old frame at the thrift store. Then I would get some screening and cut it about two or three inches larger than the frame. Using a staple gun, I would attach it to the back of the frame. Just pull it tight and then staple it down all the way around. THen trim the excess and add a picture hanger.

Buy and old picture frame, buy wire mesh the size you want at home depot. Cut with wire snips wearing gloves, and staple to the frame with a strong staple gun made for that, not for paper.

here is info for you Susan

https://www.youtube.com/watch?v=A4HJzGeIBYE

Here are some ideas: https://www.hometalk.com/search/posts?filter=earring%20holder

Heres a great Vid that may help you out

https://www.youtube.com/watch?v=Nf56Uvf0tG4

I've seen lots of different tutorials on Hometalk for jewelry holders. Have you tried the search bar at the top left? If you have hundreds you're looking to store, your dimensions will certainly vary from others but you can scale up.

Get a old window take out the glass get chicken wire or even a screen will work staple a piece on the back to cover the whole opening in the back then turn around and hang your earings you could wrap some pretty satin ribbon around the fram to dress it up or blue some pearls or crystals in the corners