I don't have much for mastering because i've yet to get Pro Tools on my computer, so usually i also work in Audacity or Reason. When i am on Pro Tools at TAFE (college) I like to use the Stereo Widener on the Master channel input to open the track up and give it some more stereo depth without any extra equalisation, i would like to find the Audacity equal if such one exists.
Limiter is pretty much a fast-attack compression and it just keep the track from clipping, so if you already got a limiter then you don't exactly need another compression, you never want too much compression on your tracks.
Equalising also helps, I do something different for every composition and it's something that im still learning, sometimes for example i put my high mids a little bit up at around 2-4k and only at about 5dB but only if it works, and most of the time i find it works out pretty good, particularly for dance music, along with some low end tweaking. i like my mixes to be full but not exactly too thick if that makes any sense. Reverb always livens things up as well.
Mastering is the correct term. I'm only learning myself but you have got a good idea yourself. It's also good to get a decent pair of monitors to get a good audio perception, something that i am investing in myself.