I like using a mix of a lot of plain topsoil, and some coconut coir. This mix allows me to get away with misting the substrate once a day, then doing an overall moistening of it. I used coconut coir in the past, it's okay, but I didn't personally like it, so I mixed it with topsoil, and it works great (for me). I also found that topsoil is extremely cheaper than coconut coir. I paid, I think around $14 for two small bags of coco coir, and under $2 for the topsoil which probably has more of it than the coco coir packages.