I don't mean to sound like I'm dumping on systems. They do have a place. It's best to not be ignorant on them. But like the end goal in most pool things, I think it's best to practice it until you don't have to think much about the systems. Every one of our minds work a bit differently so make sure whatever you're doing, you do you.
There is a
Dead Aim Kicking Academy document that is really quite useful. At one point before taking a 10+ year break from pool I had all that stuff memorized. I barely ever gave up BIH but I couldn't make 3 shots in a row.

After getting back into pool for the last several years I've not really looked at any system based stuff. It really is useful but at a certain point trying to use 20 different methods/systems just feels like being lost in the weeds. But that's one cool part about pool nowadays, the info is out there and it's fun to learn new stuff.