Perhaps the second most frequently asked question I get is: "What kind of soil do you use?" "Recipe?" "Ratio?" etc. Following are links to actual products I use. Literally daily. Nothing I use is fancy, I either order via Amazon or grab those same product at Home Depot. As for recipe or ratio - fertilizers below are mixed in as per label, although admittedly I've used them long enough to now just eyeball it, and as for the soil mix I truly wouldn't stress too much about a precise ratio. Just think tropical forrest floor is just a ton of tree debris, animal droppings, rotting plant matter, and not in any particular ratio. Even if you were to just use the soil below straight out of the bag you couldn't go wrong if you simply watered your plant as the top, visible part of the soil, starts to dry out.
More often than not I use Miracle Grow Moisture Control mixed with about 50% perlite for seedlings or orchid bark + perlite for bigger plants. I find that this retains enough moisture without staying wet for too long and contributing to root rot. Addition of perlite creates perfect amount of aeration for small seedlings, and bark for thicker roots of more mature plants.
With every single watering I add Humic Acid, Cal Mag and LiquiDirt. I don't fuss over how I water mature plants but young seedlings are always bottom watered. This, of course, is just a matter of personal preference. Each of these products lasts me about a year and a half. To large, mature plants I occasionally add slow release fertilizer like Osmocote. The 2lb container lasts about a year. I don't recommend using this on very young seedlings, it's likely to burn their young roots, especially in a hot tent or a greenhouse.
I think this is pretty much all, if I think of anything else I'll update this page.
Hope it helps xx M