I used some sort of seed starting mix because its very light and has perlite in it and just enough nutrients for a seedling. Miracle grow works fine and is only like $4. But yea you poke holes at the bottom and on the side towards the bottom and then you put the soil mix in. Put the germinated seed in there with the root tip facing down just barely under the surface, not to deep.

Then put the saran wrap over top and keep it tight with a rubberband. WORKS EVERYTIME!