I always slice my potatoes as thinly as possible into a big bowl of water. For the slicing, I use the thinnest setting on my mandoline, which is probably 1/8 inch or less.
Let them sit in the water while the oil heats up to about 400, then take out a batch, dry them between paper towels (if you don’t, the oil will pop) and fry them till they get to the right color. You could probably try baking them too, the key to a good, crispy chip is having them super thin. Too thick and they are just big, round french fries. Not that there’s anything wrong with that 😉