1. They don't ask enough questions of their lender and end up missing out on the best deal.
2. They don't act quickly enough to make a decision and someone else buys the house.
3. They don't find the right agent who's willing to help them through the homebuying process.
4. They don't do enough to make their offer look appealing to a seller.
5. They don't think about resale before they buy. The average first-time buyer only stays in a home for four years.

Source: Real Estate Checklists and Systems, www.realestatechecklists.com.