"The biggest thing people have to worry about is getting too many hits on their credit reports," says Ed Mierzwinski, consumer program director with the U.S. Public Interest Research Group.
A lot of experts advise submitting all mortgage applications within 30 or even 45 days because, if submitted during this window, they count as one on your credit report.
While the latest versions of the FICO software allow a wider window, a lot of lenders still use older versions of the software, says John Ulzheimer, president of consumer education for SmartCredit.com. That means you should play it safe and submit all mortgage applications within a 14-day period, he says.
While you're shopping mortgages, lenders may be shopping you, Mierzwinski says. His advice is to apply only to companies you seek out, and skip those that contact you first.
The other challenge is keeping your credit card balances low. To get the highest credit score, you want to keep your use of cards to 10 percent or less of the limit, and use only one or two cards, Ulzheimer says. Pay bills in full, and delay opening any new accounts until after you've closed on your home.