I love using rockwool. It absorbs & drains very well. I start off with using starter cubes and once roots starts to come out of starter cube I stick them in either a 3 inch or a 4 inch cube.
Then when I see roots coming out of the bigger cube I stick them in a pot and put hydroton under and all around the cube as a medium.
Then I just keep transplanting them into slightly bigger pots as they grow.
Once they've reached their full potential for harvest, I take the cube out of the pot and put them on a drain table that is filled with hydroton. It makes a huge bed so the roots can grow with no restriction.