of course vocals are gonna get buried in choruses and stuff because you generally make everything louder/more powerful, i like bumping up the OHs, guitars, adding melody guitars etc, so you automate the vocal to be louder during such parts and/or double track the main vocal during i.e. a chorus to make it pop and naturally bring up the level. no mix is gonna sound good with just a bunch of one-setting plugins and a constant level, you need to make the mix come alive with automation, bumping up certain things at certain points to make the focus shift for the audience. a good live sound engineer who knows the songs wouldn't just stand back during the entire performance, he would play with the faders constantly to make sure the audience hears what they're supposed to hear. if you love a little part of the vocal for example, like if the singers voice is cracking up in a good way somewhere, that would otherwise just blend in with the rest or even disappear, even though you're hearing only that every time. so you bump that up so no one could miss it. exaggerate details.
something that improved my mixes alot was mixing without master bus plugins, like compressors and limiters. sure, it helps glue the stuff together, so it's easier to get the levels right. but if you nail a good mix without any mb plugins, your mastering process will be loads easier and everything will sound good and work together regardless. instead of relying on a masterbus EQ bringing up the clarity of it all, boost the things that really need high-end, like cymbals and vocals, instead of making a mess with a mastering high-shelf. bottom line, mastering should improve an already good sounding mix, your mix should never depend on a mastering chain. if your mb compressors is hitting like 6 db GR when you're mixing the instruments and everything sounds good, then you add the vocals and they don't quite fit, then you start changing your mb because there isn't enough room, then the instrumental mix is just gonna come apart. headroom is the key. doing mastering last and seperately is especially helpful when you're mixing several songs to sound alike, like an album or an EP. just tips of course, there's no right and wrong, but it might help cause it sure helped me.