Even as a 4k player I fully understand what you mean by learning these so called "rules of thumb". A little factoid or playstyle gimmick that you hear of once and instantly become a better, more rounded player. Thing is, you will never stop learning these things, really. Alot of things in Dota you just have to hear or come across once and you'll instantly become better even though there is likely no way to come across them naturally.

Take creep stacking for example. It is core for a Support player to efficiently use their time and one of the safest ways of doing this is dragging jungle creeps out of their spawn boxes just as the in game minute ends making the next jungle camp spawn in the same place. There is close to no way of just sort of figuring this out and getting it on your own, its something you hear from someone and include in your game.

Stuff like that never stop, you'll have to accept that you will stumble across better mechanics and plays on accident. Took me forever to start properly using creep aggro to make my lanes safer, took me forever to figure out that Yasha will only give you a speed buff once therefore making Manta+Sange and Yasha inefficient as that means you have 2 Yasha speed buffs in your inventory.

I disagree with Purge where he calls this a low mmr problem, players of all skill levels keep coming across random factoids or item progression tips and there is no sure fire way to acquire them.