I really like the method that Quality Captives uses. I take sandwich tupperware and put some coco Bark in it. Soak it really well and put in a bunch of springtails. Then when the time is right after a couple of weeks i put the whole container ( or somtimes just hte bark) into the viv. I usually layer the top with spaghum moss, and sprinkle some bakers yeast on top. Then i put leaf litter over the bakers yeast and let the mealing begin. This method is great for tinc class froglets and thumbnail froglets and frogs. I have also noticed that all my larger adult frogs will eat springtails if possible. This gives you a long term semiself sustaining population of springtails right in the viv. If produciton ever drops or the culture crashes you can always remove and replace. This method also help as far as overheating the springtails because under the moss and amongst the coco bark, the conditions are really nice for the springtails. I hope to someday try a few different varieties of springtail because they are my favorite food item.
I usually sprinkly a few fish food flakes or yeast at the front of a vivarium to bring the springtails to the top. That, in turn, makes the frogs come to the front of the vivarium and this just increases my viewing pleasure It kills two (jor 3) birds with one stone, my springtails get fed, my frogs get fed, and I get to see my frogs more. Just make sure not to put too much fish food/yeast in your viv. Hope this helps!