Today I was flying out of CYBL on IF and I had my first experience with mountain waves! The reason I had not had that experience before was because I had autopilot on, but today I trimmed out the cessna 172 to hold an altitude without autopilot and I had a headwind of around 22KTS flying over the ridges of the canadian rockies, so when I got near a ridge my plane went up about 50ft pretty fast and the turbulence got a little lighter, then when I got on the leeward side the turbulence got worse and I dropped anywhere from 15-50ft, it was really cool and fun, If you want to do this just trim out the aircraft to fly at around the altitude you want because the autopilot corrects for mountain waves.
You can really experience the winds funneling, especially if you are in a valley. Some fun airports in valleys are Innsbruck and Paro Intl. Those are some really fun approaches and are must-dos. :)