I have several seedling phals. One came to me in sphag, and I am keeping it there til it gets a bit bigger...but being very careful not to overwater. The rest I am treating just like the bigger guys, but on a small scale. They are in (fine) bark mix, in (small) plastic pots, and get watered just before they dry out. The hardest thing for me is keeping water away from the crown...its harder for me on small plants, but very important.
Good luck.