I just imagine I'm a whale with lots of BTC looking to take profit. I'm not, but if I was I'd be wanting to dump when market confidence is looking a bit shaky in order to provoke a panic so I can buy back lower. In the current environment that probably means I'll be dumping at the point a sustained uptrend stagnates, or to put it another way: at the point greed turns to fear. Psychology is everything, the trick is extrapolating market sentiment from numbers and news. Of course you need to get in before the whale. The last couple of corrections I managed to spot ten minutes or so before they happened, but judging the scale of the correction is much more difficult, it's easy to think you're catching a falling knife only to discover you're holding a dead cat.
Disclaimer: I'm no expert.
Edit: You need lots of information to do this. I have tickers for multiple exchanges open all the time, am constantly reading these forums and all other bitcoin and general economic news I can get my hands on. Going by the gox/USD ticker one may think a correction in imminent, but looking at the btchina ticker shows me this isn't the case. Of course now I've said this it's going to crash just to punish my hubris
Congrats on spotting the recent corrections right near the top. Yeah, you pretty much have to watch the tickers around the clock to have a chance of doing that. And, as you said, it's important to watch multiple exchanges.
The last couple hours, BTCChina is rocketing up fast, while Gox and Stamp are barely going up at all. This is exactly what I expected. I'm sure there will still be some more upside on all exchanges, maybe a lot of upside, but it will be more in China compared to the others. And I'd give this rally 3 or 4 more days, tops. My best guess is actually 1-2 days. We'll see.