I play bass and "mix from the stage" for my band about half the time, usually in venues we play regularly. It's so much better when we expect the pay to be sufficient to pay for our sound engineer, but it doesn't take away TOO much joy for me to do it when we don't want to fork over the extra money or it's a familiar room.
We have an Behringer X32 rack, and the ability to save scenes does help a lot. No IEMs yet, unfortunately. All 4 members of the band sing lead and backup vocals. ONE BIG TIP I'll give you is to train everyone who sings both lead and backup vocals to move their heads back away from the mic when singing backup. This helps when there's nobody out front to ride vocal faders on a song by song basis, and allows the group of vocalists to mix themselves based on distance from the mic. It takes discipline and they don't always remember to do it when in the moment, but it's something to work on.
Our typical order of operations:
1. I set all the gains, looking for that -18dbFS sweet spot.
2. I then set the wedge mixes so that each person has their own vocal set as the loudest thing.
3. Next each wedge gets with the other three vocals set 5db lower than their own vocal (except for one member who likes them all the exact same volume).
4. Then we add in the guitar rig and keyboard DI to everyone's taste, bringing them up from zero until they are just enough.
5. We don't usually put anything else in the wedges.
6. We do one soundcheck with me out in the room not playing bass to get the sad, bassless mix right.
7. Then I go up on stage, our electric banjo player (he plays it through a pedal board and guitar rig) starts a basic loop, we all start playing to it and singing general nonsense words in key while he goes out front and does the final mix that includes the bass.
I'm sure there are many times the mix isn't great at certain points or songs, and people just don't let us know. But I think for the most part, as someone else said, a good mix is the ear of the beholder, and people won't care too much. I still HIGHLY prefer to hire a dedicated engineer whenever possible.
This reminds me something funny. At a recent gig, we did a split bill with a touring band that we helped get booked at our home venue. It's a place we've been playing multiple times a year for about 9 years. You know, that bar you always hangout with and know pretty much everyone in the room every time you're there. And all your musician friends hang out there when they aren't gigging.
Anyway, I ran sound for the other band who played first, then I set a tablet up on a stand in the corner of the floor by the stage, facing the audience area. A member of the other band agreed to keep an eye on the sound a bit and tweak it if needed during the first few songs. I don't think they had much experience running sound, but as a musician they were capable enough to fake it.
The funny thing was that throughout the show, I saw various friends walking up to the tablet and studying it. Some studied it for a long time, and then started tweaking things. At least 2 or 3 different people did this. I know, this probably scares the crap out of everyone reading this. But crowdsourcing the sound that night, with that crowd, in that room, worked really well actually. It's hilarious to think about. Probably won't make a habit of that, but it was an interesting experiment
I still maintain that by basically taking feedback issues out of the equation via IEM, it makes your life easier. But clearly, you are FAR more experienced and skilled in live sound than I am - I'm barely beyond rank amateur in that department lol.
