These require a little time to make, but are worth the effort. Once the skins are fully dehydrated, they can be frozen indefinitely before thawing and frying.
Make sure the skins are fully scaled. Pick off any stray scales. Cut the skins into large pieces.
Bring a medium pot of water to a boil and add a few tablespoons of salt. Bring the water back to a boil after adding the skins and boil them for at least 1 minute, and up to 5 minutes for thick skins like sturgeon or shark. Most fish only need a minute or so.
Remove the skins from the boiling water and lay them, meat side up, on a cutting board. Carefully, using a butter knife, scrape away all the meat and fat from the underside of the skin. This is a gentle process. You might rip the skin a few times, and that's OK. When each skin is clean, lay it on a dehydrator rack.
Dehydrate the skins fully. You can do this at a range of temperatures. I go for about 140°F, but you can go higher or lower. You could also use your oven set on low, especially if it is a convection oven.
When the skins are completely dry, so they snap when bent, you can fry them now or store the skin for a couple days in the fridge; you can also freeze them. Fry at 360°F one or two at a time. They will puff up instantaneously. Fry until the bubbles stop, about 30 seconds.
The moment they come out of the fryer, dust with salt and whatever other seasoning you like. I love using Mexican Tajin.