dropper lines

I used to use droppers all the time. I find myself using them less as time goes on. First off just tie leader onto bend of hook. Use about 18". I use a slightly lighter leader weight, that way you don't lose two flies. The reason I'm getting away from tandem rigs is that it's hard to fish one without foul hooking alot of fish. Also I really believe I get a more natural drift when I use only one fly. It's also easier to change setups, which I seem to do very often.

I'm similar to thedrake here.  I fish two flies fairly often, especially on streams where I'm prospecting more than targeting.  Similar setup but with two things to note.
 
First, you can use the distance between them to your advantage.  I will often run a pretty heavy fly on the point to get the whole setup down without shot and then run an (up to) 18" dropper to a small fly.  That will let the tiny fly drift naturally in deep water where a lot of shot wouldn't have worked as well.
 
Second, I don't tie to the bend of the hook anymore.  As mentioned above, it is a pain in the butt if you want to change the point fly.  If I'm going to be fishing the same point fly all the time, I'll tie to the eye of the hook instead of the bend.  If I am prospecting then I tie the dropped line to the tippet above the point fly.  I use a standard improved clinch knot but instead of using the eye of a hook use the line as your standing post.  Then when you want to change the point fly you can slide the dropper knot up the tippet, change the point fly, and slide it down again.  It also helps when you are trying to untangle to have the dropper line separate from the main leader.

Thanks
Rick