I spent 3 hours today trying to get a good sharp shot of some tiger lillys with a tripod and without, using my 18-135 and then my 18-200vr with kenko extension tube....the shortest one worked best and I actually did better without the tripod than with.
I don't do this kind of shooting often and I'm sure practice, practice, practice makes it easier.
Took most of your advice, Dumpy. I did moving back and forth mostly by zooming and then manual focusing