I have used Super Soil Palm and Cactus Mix, Kellogs Palm and Cactus Mix and Black Gold. Then I still add some more perlite or pumice in it, just got to make it really well draining since I leave most of my succulents outdoors and our rainy season is winter time. If I also get around our local Japanese bonsai store in San Francisco, I get some small baggies of akadama, kanuma and their smaller sized lava rock, I like to mix this in with the cactus mix and put them as top dressing on the containers.
I never liked the Miracle Gro mix, they keep adding those fertilizer additives, which I do not like for my succulents, their soil seems more suitable for other types of tropical container plants.
