Here is what i posted on another forum. It has worked well for me.

Switching from a typical potting soil found at Home Depot to an expensive soil found at hydro shops has been huge for my outdoor grows. Here is my current mix:

5 parts Foxfarm Ocean Forest
2 parts Foxfarm Happy Frog
1 1/2 part perlite
3/4 part earthworm castings
1/2 part bat guano

I will also try some various organic nutes along the way but not too much. This mix drains very well but remains moist when it gets super hot.