For the best skill gain rates, you don't want to be taming the most difficult creatures possible, nor do you want to tame the easiest. What you want to be taming is something that presents a challenge while not being too difficult. That is what the "What Do I Tame" script determines for you.
Let's say you put in 80.0 taming. You want to look at the creatures that haven't been tamed before first. Our sample list says that great harts, grizzlys, and snakes are the absolute best thing to tame at our skill level. A few 2nd tames appear in the best category as well (snow leopards, panthers, grey wolves), making either the 1st or 3rd retames of those creatures fall in the good category.
Ideally, you will want to find an area to tame in that has most or all of those creatures. Our sample list had panthers, snow leopards, grey wolves, grizzlys, great harts, and snakes. We'd be better off in the forests to tame 5 out of 6 of those creatures, instead of going to arctic isle for only the snow leopards, which will mostly be pretames anyway.
If you are going to tame in an area that is very unlikely to have other tamers around, you will want to go to an area where mostly "fresh" creatures will be that fall into the best or good categories. You will then need to kill off every thing you tame in order to continue the respawn of fresh creatures to tame.
If you know the area you are shooting for will have other tamers, go to an area where most of the 2nd or 3rd retames with a best or high end good rating can be found. However, you run the risk of taming a creature you've already tamed before if no one in the area is killing any of the creatures.