For the love of God, PLEASE NAME YOUR LAYERS. There’s nothing worse than opening a Photoshop file with 50 layers that are named Layer 1, Layer 2, Layer 1 copy, Layer 4 copy, Layer 4 copy 2 (you get the idea). It makes it extremely difficult to work with later on; especially if that Photoshop file was created by someone else.
Name your layers in a short but descriptive manner. And don’t be afraid to group things into Layer folders. Photoshop even has a Note tool you can use (found under the Eyedropper tool). You’ll have a much easier time editing it later, and anyone else that has to work with the file will thank you.