Most of the guys who "self-improved" from incels to "slayers" did the customary +1 point boost by maxing out everything else they can. It is almost impossible to level up more than this. They already had the baseline attributes to do well with women, but just had to fix some easily correctible things, like getting in shape, or modestly improving their financial situations.
I suppose significant plastic surgery could help even more but, at least among men, it is still taboo, aside from hair transplants or steroids.