Don't apply for a new credit of any kind as this may affect your FICO score.
Don't increase your credit card debt as this may affect your FICO score.
Don't consolidate your debt onto one or two credit cards as this may affect your FICO score.
Don't use any of your existing home equity line as this may affect your FICO score.
Don't pay off collections or charge offs as this may affect your FICO score.
If you are thinking about co-signing for a loan with a friend or family member, please think again, as this may affect your FICO score and/or the loan amount you will qualify for.
Don't borrow money from a friend or family member (gift funds are okay as long as you notify your lender).
Have your most recent two years of W-2 forms, last months of pay stubs and bank statements ready.
Keep a copy of all non-payroll checks deposited into your accounts.
List all accounts from where your money for a down payment is coming from and have the funds in your accounts when making an offer, as most lenders will not allow a transfer of funds.
Identify if there are any health and/or safety issues in the home you're planning to purchase including missing flooring or cabinets, termite or water damage, mold, no heating system, etc., as this may affect your ability to obtain an FHA or VA loan.