KEEP LAYER STYLES FROM AFFECTING NEW WORK

As you know, when you apply a Layer Style to a layer, it affects the entire layer. For example, if you apply a drop shadow to a layer, everything you do on that layer will have the same drop shadow applied to it. But what if you've applied a drop shadow and you want that shadow to remain, but you want to do other things on that layer without having an automatic drop shadow added to them? Here's what to do: Create a new blank layer by clicking on the Create a New Layer icon at the bottom of the Layers palette, and drag this new layer beneath your layer with the drop shadow. Click on your drop shadow layer (to make it the active layer), and then press Command-E (PC: Control-E) to merge it with the blank layer directly beneath it. This will remove the active effect from the layer (so it no longer applies a drop shadow to new things on the layer), but it will leave the shadow effect on the objects that were there before the merge.