Mad badger,
I think this is a very interesting issue and gets to the heart of trading. The first question is where should you buy. Taking Long trades as an example, say you've identified an area of support in an uptrend. This could be a trendline, moving average, previous area of support or resistance, pivot point, ect.... Do you somewhat blindly buy right at this price (or a little bit higher to ensure a fill), or do you wait to see if it bounces first? There are pros and cons for both approach. Buying first, asking questions later can get you in at a good price. In fact sometimes the market will first bounce at areas of support and only come back to your entry if support is going to be ultimately broken. Therefore, you can enter right at support and quickly trail your stop up to breakeven. On the other hand, blindly entering at the area of support can lead to catching a falling knife as price rips through support.
As for confirmation, you will have to pay for it. If you wait to see it bounce, your risk will be much higher as price has already started to move. Oftentimes, the market will bounce at support and perhaps form a hammer, which some might see as nice confirmation. Others might see a stochastic crossover, others the MACD turning up, and others may see the highs of prior bars being taken out. All of these different levels of "confirmation" basically lead to higher prices if you want to enter the trade (for a Long setup). However, since prices bounce so frequently around levels of support, I'm not sure how much better is the probability these trades will actually work if you see a good bounce.
I think your answer probably lies somewhere between these two extremes. Try to avoid catching the falling knife, but don't pay up too much for confirmation by not requiring too much confirmation. After all, trades are profitable because you properly took and managed risk.
All of this only speaks of entries, but exits are just as important (many think they are more important). I recently raised this same question in another thread about whether you should exit a trade immediately if a trade goes against you. I think that if the premises of your trade entry are violated (support being broken) that you should exit the trade. The slightest break of support could be a shake out, but you have to be reasonable as to what you define as a shake out or stop gunning. This always raises the ongoing debate of tight-stops versus wide stops. I like medium stops that adjust for volatility. Just some thoughts. jbob