[MereInterest]

As with most things, it is largely a matter of practice and experience. There was a time when I was fast enough to take lecture notes in LaTeX, in courses where there were many formulas to be typeset. I did get an odd look from a professor one time, where at the end of a one-hour open-everything exam, I turned in a typeset pdf rather than handwritten answers.

Sadly, I am not as proficient with it as I used to be, as it has way too much esoterica in getting the exact layouts you want.