Check out this great tutorial from Design Reviver on drop shadows. Digiscrappers have been trying to make digital art items look realistically like paper for some years now, so I know a bit about drop shadows. In fact, you can buy srop shadow actions from digital scrapbook designers to make it easier to make scrapbook pages.
This is a nice tutorial that goes over a few different techniques that may be new to us. It's well worth checking out.
And remember - stay away from huge drop shadows that make it look like your stuff is floating way over the page. Subtle and realistic is the key.
