1. Have a vision
By this I mean have a good idea about what you would like the whole house to look like once you are finished. Many times we go room by room, and end up with a mix of styles and materials. If you stick to a unified vision, you will end up with a great home.
2. Buy recycled or used materials
Most cities have stores that sell recycled building materials. Sometimes these materials are cheap and have more character than what you get at a big box store. There are also the Habitat For Humanity Stores and Craigslist where you can buy materials. I bought three matching windows for the price of one, but it took a lot of patience and visiting these stores over the course of a year before I found the right deal.
3. Tackle one project at a time
Remodeling a home can be a daunting task and one can easily get overwhelmed. Take it one step at a time. Finish the bathroom before you demo the kitchen. Having just one part of the house in disarray will make life feel less chaotic, and help you keep things manageable and within budget.