Don't invest more money than you can afford to immediately lose. I learned it from mtgox. It was a stress test. Now this is easy. I keep my day job and let the profits ride until I need something or see a better opportunity. Hang in there. It's an infant of a market. No regulation to speak of yet.

Divesting your initial principle as soon as you can might help you sleep better. Everything left is profit and risking that is a luxury few investors consider.

Diversify with the alts - like, a lot. Yesterday wasn't that bad for me. BTC may grow 5X in the next year but it'll never grow 1,000,000X again. An alt with a brilliant idea that solves real world and bitcoin problems could. DYOR. Diversify. Insulate.

Most of all, HODL.