If you're a lineholder, the process is relatively straightforward. Starting on the 20th, you can submit drop requests via Seniority Trip Trade or Crew Companion for next month. Whether that gets approved or not depends on your base, reserve coverage, percent of flying in open time, direction of wind, whatever. Some bases say it's impossible, others it's fairly routine. If drop is approved, it's off your schedule. You can do pilot-pilot trades and pickups in base as well through Crew Companion. If you've got a question, talk to trip trade desk sometime other than 1100-1500, they've always been very helpful for me.