Discount warehouse clubs such as Sam’s Club (Stock Quote: WMT), BJ’s Warehouse (Stock Quote: BJ) and Costco (Stock Quote: COST) cut the cost of products by anywhere from 8% to 15% as soon as they hit the sales floor according to Michael Clayman, editor of Warehouse Club Focus.

Saving 15 cents on the dollar is great, but remember that just joining these clubs for a year can cost $40, or more, before you buy anything. It therefore pays to be smart about how you work your membership.

Whether you’re on the fence about membership, or eleven-and-a-half months into an existing one, here are a few tips to help you get more out of your discount warehouse club experience:

1. Take charge of bonus credit. Money may be tight in the current financial climate but discount warehouse clubs offer incentives above and beyond their daily deals in order to get shoppers through the door.

Shoppers at BJ’s Wholesale can receive an annual reward of up to 2% for all purchases. All Costco Executive-level members get 2%, too. The reward is applied to next year's membership with the balance being held for future purchases. That means if you consistently spend $400 a month at BJ's for a year, at year's end you can expect next year's $45 membership covered, along with a $51 store credit.

2. Think “outside the box” discounts. According to Clayman, many discount clubs provide financial, health and personal care service discounts, as well as savings.

For example, BJ’s Wholesale Club members can get a 10% discount on home and auto insurance from Liberty Mutual.

Sam’s Club members can get as much as 30% off of the cost of a doctor’s visit if they enroll in the OptumHealth Allies plan, which ispart of the United Health Group (Stock Ticker: UNH).

3. Consider a membership upgrade. Spending a little more for membership up front can mean more significant savings down the road.

For example, consumers who purchase prescription medication through Sam Club’s Advantage Membership, which costs $40 per year, can get as much as 25% off of drugs, such as Ambien CR (Stock Quote: SNY), that they buy at Sam's Club. Sam's Club Advantage Plus members, who pay $100 a year to join, get additional savings and the added flexibility of being able to fill their prescriptions at other stores such as Wal-Mart (Stock Quote: WMT) and Neighborhood Grocery (Stock Quote: WMT). According to Sam’s Club spokesperson Susan Koehler, Advantage Plus members, and those who upgrade, can receive a $100 certificate that they can put toward savings on vacation packages and select cruises. 

Costco's Executive Members pay an extra $55 per year for their top tier status, but if they use Ameriprise Auto & Home Insurance (Stock Quote: AMP) to insure their car, they get one-year's free roadside assistance.

4. Clip coupons. Costco and Sam's Club do not accept manufacturer’s coupons, but BJ’s does according to Cathy Maloney, vice president of investor relations.

5. Share and share alike. If lugging 24 oz of Brooks Rich & Tangy Ketchup or 32 oz of Dukes Mayonnaise 32 oz isn’t your idea of a good time, you can save a few bucks (and your back) by shopping with a buddy and then splitting the costs. Sharing is saving. Happy shopping!

Editor's Note: This article, originally published on March 16, 2009, included information obtained from representatives of Sam’s Club Discount Warehouse that was incorrectly attributed to Costco. This is the corrected version of the article.