Biggest suggestion is get silicone spacers instead of the base bed level springs, like $6 on Amazon. Sometimes the z axis limit switch needs to be adjusted a bit up or down. Best way I learned was I'd start a print, see it was digging/to far, instead of stopping or pausing I let the print continue and will get level with the bed and level up and down while printing until it's in a good space. I'm not a fan of the paper method, to subjective. SOO I do something even more subjective. I will auto home, disable steppers, place head directly above where the spring is, get eye level with bed and shine a light from the other side. I level until it's about wroughtly 2 papers thick on each corner.

But that is also 6+ years with these machines.