Don't allow any individual to have more then 50 percent of the knowledge for a project. In other words, don't become too reliant on one employee. Avoid Christmas deadlines. They're more likely to lead to headaches than big sales. Don't scrimp on planning.
Foresight is a lot better than hindsight.
Re-educate middle management and make sure they're with the program. Our advice is to get them out of the way. Scale is king. Make sure a site can handle at least two or three times the amount of traffic you expect to receive. Don't try to be everything to everyone.