First Wecome to the forum. You will get amazing info given to you but you will get even more stuff if you do a little R&D. If you scroll down to the bottom of the page where the forum topics are, you will see a search box, Enter "Cactus soil mix" , "fast draining soil", Al's gritty mix, soil for Christmas Cactus, soil for Epyphyllum or anything that strikes you.You will bring up more info than one could shake a stick at. It is not that people are being shy, it is just that this question is asked a lot . and some of us that know the answer get tired of writing it . Read a bit and then come back with more questions. It is a great feature and one that should be used . I was not aware of it for a long time.

I make my own. Search "gritty mix" for the recipe I use.

If you want store bought, one of the best I have found for jade tress is Hoffmans Bonsai mix. It's the closest I've found to what I make.

I'm glad you asked that question mnkosch as I'm just beginning to grow succulents indoors (in glazed pots) and find the soil mix to be more important now, than it was when I had my potted succulents out in terra cotta pots on my pool decking in 90-105 degree temps. Now I know where to look for more information.

I go into making soil like a cook. This time I am feeling lazy and bought some organic potting soil and I am mixing it 1 part potting soil to 3 part inorganic ( perlite, crushed grant, expanded shale ( no pumice in Texas)) Maybe add some pine park fines.