Sometimes when I read about music production and audio engineering stuff I come across ideas that I personally wouldn’t use in my music, but nevertheless could be interesting – at least in theory – and perhaps someone else dare to try.
Here’s one: record your “as is” mix from your monitor speakers, using a couple of microphones, and then blend the recording with your final mix.
This could add vibrance and “realism”. It could of course also clutter your mix if you overdo it. If needed, try to poke the recording to play with the phase relationship.
Recording your mix like this can add some analog imperfection by revealing a little of the studio’s ambient, and the colors of the mics, preamps and monitors would also print this sound layer. And you need not to record in the studio, you could put the monitors in a (non-acoustic treated) reverbant room, or record with an opened window… You get the drift.