If I just need to move them, I use a clear glass. For smaller frogs you can use a tumbler, but bigger frogs use a plastic FF culture container. They can't see the glass, which makes it easy to put the glass/container down around them. Then just shoo them with your hand, and they jump up on the side of the glass. Turn the glass over, put your hand over the top, and carry them to their new location.
If it's a longer trip, you'll need a container that has a lid. Again, FF containers work great. Don't forget to ventilate the lid by poking holes in it, and put a piece of moist paper towel or spaghnum moss in the bottom so they don't dry out. When I had to take my female cobalt tinc to the vet, I used that method.
The advantages of using a clear glass/container is that it is less stressful on the frogs. Even if you need to direct handle them, once you have them in a smaller container, it is much easier to pick them up.
As for direct handling, remember, direct handling is very stressful on the frogs (and they can literally die from stress), and should only be attempted as a last resort. I watched the vet while she held the tinc for examination, and she held the tinc with her thumb over the tinc's back, and the two legs hind held behind in her fingers so the frog wouldn't jump out. If you are going to handle them, remember to wet your hands first, and remember not to hold too hard or you risk breaking bones, or worse.
With thumbnails, pumillio, and other tiny frogs, it's best not to handle them at all because they are so small and delicate. It is very easy to squeeze too hard and kill them, if the stress doesn't kill them. Try to treat them while they're inside the glass/container.