some thoughts on the continuation bet

I have been thinking alot lately about what initially seems like a very small and uninteresting move in NL poker, the continuation bet. The deeper I think about it the more complex it becomes(what about this game doesn't though, right?). I remember after reading Harrington for the first time I immediately began continuation betting every hand that I had taken the lead with a pre flop raise. This would usually lead to me laying down in a fetal position to every re-raise i faced when I wasn't holding nuts. Obviously this isn't the way to win tournaments.
I have begun to make some interesting changes in my game and one of the biggest changes I have made has to do with my continuation bets. Not only the frequency of the bets but also the size of the continuations I do make. I remember immediately post Harrington it would always be just as he outlined, 1/3 or 1/2 pot. I played as if these amounts were the only way to bet and anything else was just not "good" poker. I have started to vary the amounts of my continuation bets and have found that a good amount is around the size of my pre flop raise. For example: blinds 100-200, I make a late position raise to somewhere between 500-600, BB calls making a pot of about 1300 going to the flop. My cont. bet in this spot would probably be about 500-600 on a non threatening board. If the flop comes very draw heavy I have found myself making a larger continuation bet obv. to give worse odds to the potential draw chaser. By making my cont. bets about 100-200 less than I would previously I can save alot of chips when I am re-raised over the course of a tournament which is very important especially in the early to mid stages.
I have also become alot more selective about the spots where I make a continuation bet. I would guess that in the past my percentage of hands that I cont. bet was probably 80% or more. Now it has become ALOT less. I have finally realized that not every spot calls for me to bet post flop. If it is checked to me and I have a nice flopped draw I will more likely take the free card on the turn than I used to. Also I have stopped my cont. bets when I flop air in a multi way pot to damn near 0% of the time, its way too likely someone hit enough that they will at least call if not pull off the always popular check raise. I guess a good summary is that my aggression has become more selective and thought out, which cant be a bad thing.