I've been using square plastic pots that have extra holes in the sides which have been growing well.
Amazon - Square pots

I also have some very very large perlite to keep it from getting too packed.
Amazon - Perlite

But like the other commenter mentioned, get something with lots of air holes or a material that breathes.

You're welcome! Specifically, this is what I use:

Perlite (though that's a lifetime supply) could probably get this instead
Coconut Chips
Fox Farm
Worm Castings