1. Look Over Your Credit Scores
You need to get a copy of your credit report from the big three (Equifax, Experian, and TransUnion) and look them over for wrong entries. It is not uncommon for items to be mistakenly reported on a credit report. It will only take, however, one item to adversely effect your credit score. Bring it up to where it should be by trying to correct anything that is not where it needs to be.
2. Raise Your Credit Levels
If you find that your credit really is not at the level where you feel it could be, take some time (if you can wait) and raise it. This can be done through credit cards that report to the credit bureaus, taking out short-term loans and paying them off on time and quickly.
This could be a key factor in getting a mortgage worth having. The interest rate that you will be able to get is largely based on your credit scores. Generally all three scores (or more) will be averaged and that is the figure that the lender will base the calculations on.
3. Reduce Your Total Indebtedness
It is always a good idea to reduce your indebtedness before applying for a mortgage. While you can have indebtedness, and even bad credit, you get the best rates when your indebtedness is about 28% of your income or lower. Having more than this will limit the size of your mortgage possibly more than you want. While it may be possible to get a different kind of mortgage, such as an ARM, it may not be the best in the long run - depending on what kind.
Reducing your debt will prove your ability to pay. You can pay off some credit cards and other small debts by consolidating them with 0% APR interest credit cards for their introductory offer, but you really don't want to close all of those credit cards. Leaving one or two open, perhaps even with small balances, could be more helpful to your credit rating than closing them all down.
4. Get A Larger Down Payment Ready
This will help you tremendously by reducing the overall amount that you need to borrow. The more that you can put down means that you are less of a risk to the lender. They will trust you more and give you a lower interest rate. Your goal should be somewhere in the vicinity of about 20%, if possible.
Another way to save when you actually start shopping around for your mortgage is to compare a number of mortgage quotes. Look for the best deal after you understand the terms and your various options. Even if you do all of the above to help get the best rate, you could lose it simply by signing on to the wrong deal - so be careful.