I'm a hydro grower, but I thought I'd share my propagation techniques with the soil crew.

I grow in 100% perlite and start seeds in 2" "net pots". These are little, plastic pots that have slits cut in them to allow water and nutrient to enter and roots to exit.

I place the net pots filled with perlite into a cut-off chunk of 2" black ABS pipe and set the whole thing in a 1/4" puddle of nutrient (liquid plant food) until each start has several 2" to 3" white roots.

At that point, the plant, roots and all, can be shaken free of both the perlite and the pot and can be transplanted into whatever medium you desire.

There are pictures showing this in my Web site "Gallery". The URL is in my profile.