Never microwave pizza. That thing with the oven is okay, if you must, but it's more work than it's worth for me.
I almost always end up with ReaEQ on my master bus. I don't usually use it for anything other than "bookending" the mix with an HPF down around 20-30Hz and an LPF at the other end usually around 18K.
Very rarely I will use an instance before a tape sim or compressor boosting in the low mids to add a bit of crunch or hair or whatever you want to call it, then I'lll usually undo the actual EQ curve with a second after the distortion. That doesn't happen often, but it can be cool in certain situations.
I almost never have to use an EQ at this point to fix anything. As mentioned above, it's almost always better to fix the individual tracks and/or re-examine the arrangement itself.
I have a few "color" EQs, but I never use them. ReaEQ is awesome, extremely versatile, and free. It really is the only one I need.
I've only kind of half-assed mastered a couple of albums since I switched to
Reaper, but ReaEQ is the one I have and will reach for on that as well.