If you already have the small stumps you have gotten some good suggestions on how to get them out...
But if you have future stumps, with trees still attached to them, then within limits I have found it best to push the trees over with my loader, and in doing so, cause the stumps and maybe half of the roots to pop out of the ground. Then a push with the loader, expecially if you have a tooth bar on it, with a little lift can pop the whole works out of the ground.
Tree is out and you never got to the point of having to deal with a stump!
A second advantage of doing it this way, is you can get most of the dirt off the roots, by lifting the base end of the tree up, and dropping it a couple times.
Nothing is 100% foolproof though. Sometimes a tree will break off (or just bend) and you have to deal with the stump.
Just throwing this out for consideration. Myself, after getting my tractor, I cut off a number of small trees before realizing it would be better cut them up AFTER I popped the whole works out of the ground... /forums/images/graemlins/blush.gif