I keep a supply of large sized, cleaned yogurt containers, for potting up seedlings once the root is about an inch or longer.
I mix my own growing medium, by adding soil, peat moss & some perlite. Once filled up with mix nearly to the top, I tap the pot to settle the mix. A tooth pick works well, to easily create a place to insert the seedling root into. Gently mist with water to help stay in place & if the seed coat hasn't come off, continue to keep it damp, or very carefully help remove it while moist, if it gets stuck.
