I've read some stuff online, but everyone's using soil from shops it seems. I picked it from a farm nearby, crushed it as fine as I could, mixed it with my own compost (various vegetables and leaves), after a while outdoors all of it just gets processed by bacteria, it quite literally disappears, all of it becomes soil.

When putting it in the fabric pots (really good stuff, forget anything else) I mixed it with a small amount of pebbles and twigs to prevent it from compacting (which severely impacts growth, as roots can't push through it); I had nothing else and that seemed to do the trick.

But the thing is I used a makeshift metal cylinder to fill the pot with soil in the center and a layer of pebbles all around and at the bottom. The idea was that the plant would grow and get nutrients from the soil, then as the roots grow out into the pebbles they'd get more oxygen and water.

It's actually sort of a soil/hydroponic hybrid setup if I think about it. Seems to have worked great.

I also used simple NPK fertilizer, the plants react if you use too much (leaves turn yellower, tips start burning), so you know when to stop.

There's a lot of information out there, but honestly I learned more with hands-on experience than from reading dozens of articles and forum threads. I thought it would be rather simple, but it's definitely not just "plant it and forget it". I appreciate plant life more now, it's quite fascinating when you get into it haha.