MusicTechHelpGuy walks through setting up a general-purpose vocal compressor in Logic Pro, using the Vintage Opto circuit as his starting point.
On the EQ before or after compression debate, his take is simple: skip the theory arguments and trust your ears. Try both orders and use whichever sounds better for that vocal.
He also flags a common issue: if a vocal is compressing far less than the threshold and ratio suggest, the input signal is probably just too low. Raising input gain first gives the compressor something real to grab, without needing to slam the threshold or ratio to compensate.
He closes by comparing release times, showing how a slower release holds the compression longer and suits a non-percussive signal like vocals better than a quick snap-back setting.