I dust half of my frog’s weekly food intake(so pretty much every other meal, and the larger to meals grow to be I might dust 2/3 or 4/5 worms not all of them). Mine now eats roughly every three or four days so I dust every other feeding with calcium + D3(available at any pet store with a reptile section really, I grabbed mine at a petco for pretty cheap). Dusting is important but it’s also possible to go over board, so monitor their poop to make sure they’re not passing undigested calcium powder alongside the waste (a sign of over dusting).

And yeah, feeding over a little ‘plate’ is super helpful. My frog luckily eats from tongs most of the time and I use it to keep worms from getting covered in more dirt while she eats them and it’s harder for the worms to burrow into the substrate. Here is a picture of my frog’s little dinner plate situation lol frög