in my experience, practice, practice, and more practice. but "just git gud m8" isn't really helpful advice. if you don't have half a decade on hand, i can make a few more practical recommendations.
a shell that can do argument autocomplete is your best friend. personally, i use zsh + ohmyzsh + fzf + fzf-tab, but i'm sure there are other configs, and i've heard ohmyzsh is a bit of a nightmare, though i haven't had too many issues.
so let's say you're running the one rsync command this month, and you forgot the args, just tab-tab and you can search through the arguments with fzf.
you're absolutely right about that last point. my fully-spec'd t440p (4910mq, 16GB, 1080p IPS, t450p trackpad, backlit, quectel eg25-g for WWAN, the whole 9 yards) cost me less than $300 to build -- a similar machine from minifree would've cost nearly double that for worse specs. though, it should be noted, that that price gets you more than silicon -- they offer support over IRC, some sort of warranty, and i think other shit too.