in a big-studio you´d rather swap mics than de-ess
believe me:
it´s
*1) vocal technique
*2) room sound
*3) mic (not always the most expensive, but the best one for that particular voice)
*4) preamp (actually can help pretty much with voice artefacts, such as s-problems etc.)
so the difference between amateur & pro-recordings are more like:
the room is acoustically built to sound good PLUS has acoustic-baffels to be further tailored!
they have a mic- selection, not only 2 or 3 good to mediocre mics...and they often use their selection (if you have tried YOUR U47, YOUR U67, YOUR BraunerVM1, YOUR ELAM 251 and your RE20 or AEA84 on the voice and you like the cheaper one´s the most, you´ll def. use it, because your not that proud of your big, first $ 1,5k-condenser anymore, so you just HAVE to use it
sorry but I´ve seen this happen sooo often!)
you have an experienced engineer doing your vocal-edits!!!
that makes a HUGE difference: de-essing can best be done manually!
editing your doubles (focus on every syllable, do you want to use it or not??? every f**king syllable!! it takes hours, it´s a boring PITA....but it makes all the difference!)
in MY humble opinion what helps the most is -> INVEST MORE TIME/WORK/THOUGHTS
you´re asking for advice here, so that´s the first step into more thoughts & work -> VERY GOOD !
than comes mix-time.....