Personally, I use my headphones to only listen to the cued track first, set my cue/master knob to 12 o'clock to hear the combination of both so I can adjust EQ before using the fader and take off my headphones to start mixing by listening to my monitors. This works perfectly for me when using my KRK monitors at home. They are placed next to my ears.
Last weekend I had the opportunity to do a opening set at a venue and I discovered it was nearly impossible to cue and mix the way i usually do. The sound reflected right off the wall in front of me and there were floor monitors, which had a lot of bass and so the details of higher frequencies were lost. I tried to solve it by fully mixing in headphones, which i dislike.
I turned up the booth monitor volume so I was less distracted by the reflected sound, but found it hard to mix with floor monitors. To prepare myself for situations where I have to work with floor monitors, I am trying various ways of mixing; headphones only, cued track in 1 ear, split cue etc.
What is your preferred way of PFL listening and mixing?