Really, soil is made much harder than neeeds be. All you need is a soil that drains very fast (If you have a normal nursery pot of say 2 liters filled with the substrate, you should be able to take a 5 liter watering can and drain it through the soil in a matter of 1-3 minutes. You pour water in, and within seconds it starts running through the bottom. Everything is is jst sideshow. The more organic you have in there, the longer it stays moist, typically. Depending on how hot it gets, and how often you can (and want to) water the plants will determine the substrate; naturally, depending nthe species.
All the different components people put in.. I do not. I have a hand full of baked kitty litter, because it really soaks water up, and provides water for a long time after watering, usefull if you are away from home a lot. Then I use a dry broken baked clay used in filling underfloor spaces as main component. Light weight, and drief quickly. And I have crushed bark. Just because I feel that micro-organisms and fungus probably do better on them and I use solid organic fertilizer a lot, so need constant surroundings for micro organisms. but that is just my persoal preference.