There is lots of things you can do with various shortcut key combinations when working with layers to make your life easer and work smarter!
Hold down Command when dragging a layer set folder to the bin to delete, it leaves the contents of the folder intact and just deletes layer! This is a great way to re-organise your layers and much quicker than dragging them all out the layer set and then deleting the original layer set.
You can create a selection of the transparent areas of a layer by holding down Command and clicking on a layer.
You can duplicate a layer, plus any layer masks by hitting Command+J.