My master chain goes a little like this:
Using Ableton stock plugins and some that I already have cuz I'm poor
Many controls are linked to macros on an effect group on the master
EQ8 to dim down any high resonances>Multiband compression OR Glue compression (depends on the song)>Sausage fattener (veeerrly minimal - used for saturation and flavoring purposes)>if I don't use sausage fattener, I use stock Ableton saturator>EQ8 with flavoring in either highs or lows (depends on song)>Limiter6>Flux stereo Imager>Spectrum analyzer
I want to make this a little more precise, but I'm still learning how to master properly, so this will probably change in time.
I always master with audio stems at below -6dB, so I know that's all good and dandy already.