My stuff started getting more consistent when I quit studying pot growing, and started studying gardening/farming. The only thing different about weed is the extreme reaction to photoperiod. The principles that apply to tomatoes and peppers apply to weed. Good light, good drainage, good pH, and available nutrients.
What gets new weed growers into trouble, IMO, is a naive belief that you have to do special stuff, and conversely, that special stuff is more important than the basics. I see grow after grow where the grower is rambling on about the 17 things in his mix, which has given him a 3 foot scrawny stem with maybe 2 oz on it. I take simple care of a seed, and get trees.
Lotta ways to get there, no particular right one, but they all boil down to getting the foundation of good light, good drainage, good pH, and available nutrients right first.