It's hard to pin down some simple rules, and it takes time to get a sense of when the markets become too greedy or too panicky. I am not an expert yet, but I have been doing this for a while. Spending a couple of years on an option trading floor also help. Basically, the strategy works best when the markets trade within a range, which is really what happened this year for a lot of time. It doesn't work as well in a super-bull market (like 2003) or a super bear market (like 2001). I think next year will be another range-bound market again: that the market will trade within a +15% to -10% range or something like that. That should bode well for selling option premium.