Many potential borrowers in St. Louis and Kansas City are turned down for mortgages primarily due to credit scores below the required minimum of 640 and property value issues. To improve credit scores within 30-180 days, tips include: paying bills on time, keeping revolving account balances low, adding a spouse as an authorized user, applying for a secured credit card, and using department store credit cards cautiously. Implementing these strategies may help borrowers qualify for loans or secure better rates.