Depending on your credit and financing, you'll typically need to save enough money to put anywhere from 3.5 percent to 20 percent down.

If you're using FHA financing, then you need a score of 500 or higher. And in the 500 to 579 range, if you can find a lender, you'll have to put 10 percent down instead of 3.5 percent.

One exception: Veterans Affairs loans, which require no down payment.

Another cash expense: closing costs. Whatever your loan source, you'll also need money to pay closing costs, which run (depending on where you live), from $2,300 to $4,000. Get the average closing costs in your state at Bankrate's closing costs map.

Improve your chances by: Along with banking your own money, search out down payment assistance, Tiffany says. Often it's location-based or tagged to a certain type of buyer, like first-timers, she says. So do an Internet search with the city name, then the county name, along with word combinations such as "down payment assistance," "first-time homebuyers" and "homebuyer's assistance."

In a buyer's market, you can also negotiate to have the seller pay a portion of the closing costs.