I figured I would go over something that I use that is kinda not really a tutorial but more a tip.
I keep all my drop shadows to the global and then once I get to the point where I want to modify them but I have all my Layers that had a drop shadow or bevel inside folders and this makes it annoying to quickly adjust the global light.
My solution is to place a blank layer over to top of all your Folders, and then put a drop shadow on it, using this layer to adjust my entire global light.
Hope this simple tip saves you some time and prevents accidents