I'm not that experienced so maybe is issues with this, but is good to know way's if people can't or don't wan't to buy rapid rooters/rockwool etc. First I want to point out, place the seeds in the soil pointed side UP, most think down. If you pre-germinate same thing basically applies although they twist sometimes, pointed side of seed up, tap root comes out and always turns down first. I personally place my seed shells (regardless of tap root length), about half inch from top of soil without pressing the soil on top of it. Mine so far have sprouted always within 1 day usually with a pre-germinate. My seeds are years old btw. Left in a glass of distilled water for up to a week until I saw a tap root. Usually saw a root within 24-48 hours, then left in water for an extra like 12 hours. Put on a damp paper towel after in between 2 non-paper plates/bowls for an extra few days to a week until I saw like 1-2 cm of root. I read old seeds start to make a coating on their outer shell, which is probably why some took awhile and like 2 out of 12 didn't come out ever after 4 weeks lol. As said here, scuffing seeds is good for old ones. Apparently you can also help it crack open with a razor blade (along with other methods I forget).