Simplest way to fade out a song?

Eric V

Reaper has mastering plug-in vst's . I believe there is 5 ones to choose from. You really don't need Audacity.
I searched for "master" in reaper and found 2. What are the others called? This is looking in Reaper by the way.
Depending on the song and the element you could fade the
  • Master chain
  • Busses
  • or individual tracks

If I'm doing individual tracks I prefer doing them manually (fingers on faders)