21) Browse some game development web sites, read user comments on game developing forums, interact people on newsgroups, get yourself some game magazines, go to conventions... This way, you'll be able to keep up with the industry.
http://www.gamedev.net/http://www.gamasutra.com/http://www.flipcode.com/http://www.gdmag.com/http://www.gdconf.com/etc...
22) Be creative, be responsible, be ahead of others, be ressourceful. Take your project seriously and give all the attention it requires. Perfection is what you're trying to reach.
23) Be prepared! Learn what a product development is about. Yes, you know about coding, but what do you know about sound editing? How about musical score? or networking, databases, servers, business relationships, marketing, human ressources, team leadership, bank accounts and lawsuits? If your project grows very fast, it's not when you'll worth half a milion and have a team of 10 people that you'll have the time to start thinking about those things.