Tip: Saving and Stacking Layers
You have a project with many layers, and you want to save a graphic in one of the layers for use in another project... (or, you might you want to save all the layers as seperate files...)
You could turn off all the "eyeballs" except for the layer you want to save... and use Menu item File: Save as... for every layer.
But, that's a lot of work!
However, in Photoshop there is a "Script" that performs this export "save a layer" duty for you. If you are a Photoshop Elements user you don't have this choice, as far as I know.
In Photoshop look for the Script under the menu: File
Scripts > Export Layers To Files...
Set the destination and a prefix name for your files, click "Run" to execute the script... and you are done!
Drag & Drop But, what if I only want to use one layer in another document in Photoshop?
You can Drag and Drop a layer, or many layers as you want. You can even Drag & Drop groups of layers, from one document to another in both PS and PSE.
Arrange your 2 documents 2up, so you can see both of them on the screen and the layers palette for the document that contains your "source" material. You'll find the 2up button on the Arrange Documents drop down menu in the very top row of the Photoshop window.
Your screen might look like this...
To Drag and Drop, Click on layer in the sources layer palette, the layer you want to Drag and Drop onto your new document. Hold down mouse button and drag the layer onto the new document, then, let go of mouse button!
Have fun dragging and dropping!