I heard, mostly when in doubt, 350 will do, and that works fine, for most things, but not all. I also know that certain things have to be very precise with time and temp, but how do you know when you're doing your own thing? Like, a homemade pizza at 425 for 20 minutes or 450 for 15 minutes. I know hotter doesn't mean faster, but I don't know why. Why is this lasagna done at 350 for an hour and that guy over there is doing his at 375 for 45?