The soaking step is what most people skip and it makes all the difference. I had the same problem with frozen fries turning out limp and burnt until I started doing fresh russets, but I went with a 20 minute ice bath and a good pat down with a towel. If they are still wet when they hit the basket they steam and you get mush. I also found that going a bit lower, around 380, for closer to 18 minutes gives me a better crisp without the burnt edges. The thin cut tip is real too, mine were too thick at first and the middle stayed raw. Now I never buy the frozen bags unless I am in a rush.