A few come to mind: Have a good down payment. 25% is not bad. Pay for an inspection. Location, location, location. Make sure its in place that you can resell it as necessary. Get the absolute lowest mortgage rate possible. With good credit, in this era, that is not hard. Negotiate the best deal, but don't be a nozzle. Deal with a good realtor. Most, at least in my experience, are clowns. Find a good one and stick with him/her. Don't let emotions take over. Its true of everything in life, but making a purchase of this size is even more so. Enjoy your new home! There is nothing like owning your own place. Cheers!
Agree wholeheartedly with getting an inspection, picking a good location, shopping for the best rate, reasonable negotiating and keeping emotions in check, etc.