I should add that I totally stole my shadow tip from Peppermint. I believe I read it on her blog when I first started digi scrapping. That's another reason that I make my own shadow styles - so I don't have to go in and change the color code every time I apply a shadow to something.
Another tip that some beginners may not know, and that I discovered by happy accident. If you have your rulers active, click on it and drag down (or across) to set guides. Then just click on them and drag them back over the rulers to make them disappear.
Masking while misting is a favorite of mine - place what you want to be masked on one layer (alphas, shapes, etc.) and then mist on a layer above that. Use your magic wand to select what you used as the mask (make sure that layer is active), select the mist layer, hit delete, hide the mask layer and voila!