In the first, I've heard day, 12 hours, 3 days, depends who you're talking to I just leave them in the position they're laid in, the embryo is floating and will float to the top and attach. I've also heard of someone finding the embryo, and turning it to so it's at the top then marking it and leaving it in that position.
If you've ever watched a female lay, some of mine have kicked the eggs around to turn them with their back feet. I just leave them where they are, all mine have float to the top by a day or two.Yes it is, when my gecko laid, the embryos were already at the top, so i just left them there. It is a good indicator of which way they should be.
I am a Dr. in Paranoia after all.