1) Don't count on anybody to do their job rightJust because an architect has a nice office and a good reputation doesn't mean the drawings will be done properly. Just because the contractor comes highly recommended doesn't mean he won't rip you off and do shoddy work. In all my experience I've never run across a group of more shady characters than contractors and sub-contractors. You must stay on top of the entire home building project if you want to keep from losing all your money and getting a house that you hate.
2) Plan Everything about Your Home Building Project in As Much Detail as Possible Up Front
Contractors love nothing more than a home builder who isn't sure what he wants, and decides to fill in the details as the house is being built. Why? Because once the contractor has the job, he can charge you anything for changes that weren't in the contract. My contractor wanted to charge me $10,000 to add a small staircase to a room. I found a sub-contractor to do it for $1800. My contractor wanted to charge me $15,000 to add a fireplace to a den. When I asked how much he would discount the price to NOT build a fireplace in the living room, he said he would discount $1500 from the price. Trust me, when you make changes you're going to get ripped off.
3) Plan On the Project Costing 50% More and Taking Twice As Long