There's already a how to film your swing thread Filming Your Swing . But there was an off-topic discussion in another thread about how much and when to film your swing, and how you should use that tool. I thought it might make an interesting discussion, so I'm starting a dedicated thread.
Personally, I think it varies. If you've already got a stable swing that you're happy with and you're just trying to maintain, not really working on anything new, then you probably don't need to film much. Maybe just every once in a while to make sure some problems aren't creeping in. Or if you start making a consistent miss more than before, or generally start hitting good shots less often than normal.
If you are currently trying to improve your swing, actively making either major or minor swing changes, then I think you need to film your swing very regularly. I'm making major swing changes right now, and I film 1/3-1/2 of my swings in my practice sessions. My routine right now goes something like this. Warm up, do some drills (I'm on dry position and feel checks and head on the wall drill right now), hit a few balls with a very slow swing. Then I alternate hitting a few balls concentrating on the priority piece of my swing I'm trying to change and then filming a few swings (usually just one or two). Choose down the line (DTL) or face on (FO, caddie) view depending on which gives a better view of what I'm working on. Then I check the video, usually do some dry or slow swings or drills trying to address the change I'm still not achieving. Then repeat.
If you're looking for assessment or help with your swing from the video (Evolvr, a My Swing thread, your pro or knowledgable friends...), I tend to refrain from posting/sharing until I feel I've made really good progress on the piece I was trying to change after the last video I shared. No one needs to see a string of videos that all look almost exactly the same!
What about everyone else. Do you film obsessively? Never? Every once in a while? Go through cycles?
If you do film regularly, do you feel it's helped you significantly? Any favorite routines, tips? If you don't film much, is it because you don't feel like you need to (at least right now)? Because you don't like using video, disagree that it's a good idea? You don't have a camera and tripod? Laziness?