Home Depot gives customers a 10% off coupon who are moving. This can take up to 3 or 4 months because the coupon is sent in the mail. They give their employees a 20% off coupon during the holidays and the coupon can only be used by an employee. You can however use this coupon at Lowes Home Improvement because they will match any competitor's coupon.
Customers who are on Home Depot's mailing list will receive coupons in the mail throughout the year. These coupons are usually $10 off of a $25 purchase. If you had several of these you could save a lot of money.
Combining a discount coupon with the items in the store already marked down is a great way to save hundreds. Home Depot frequently marks down their items already on clearance. To make sure you don't miss a great buy, check the store frequently. If you see an item in the clearance section that has been sitting there for quite some time, ask a sales associate if they would mark it down a little more. This has happened many times. Home Depot does not want to have any liquidation items so after it has been on clearance for a week or two they are then ready to mark it down again and again.
Combining discount coupons with items already marked forty percent off of clearance price is a great way to shop. You could even stock up on several items that are on sale and sell them for full retail price.