How to Create Libraries in Photoshop

⓵ In Photoshop, click on Window and select "Libraries"
⓶ Click on "Create new library"and name your first library.

I have my libraries categorized by Overlays, Skies & Textures. You can set it up how you'd like:
⓷ In your new library, click on the folder icon at the bottom.
⓸ Right click on your new folder, select "Rename group" , then enter the name of your overlay set such as "AMP - Leaf & Branch Overlays":
⓹ Now, drag and drop your overlays into the new folder you just created.
⓺ Once your files have loaded, you now have an overlay library ready to view and drag-and-drop from within Photoshop!