Surely, you've heard advice about cutting discretionary expenses — a daily latte, for example — to save money. But what about necessary expenditures, the bills you have to pay each month? Here are five opportunities to do just that:

Save big on groceries.

A family of four spends an average of $1,300 a month on food at home. One of the best ways to lower your grocery bill is to stock up on items that are nonperishable or can be frozen when they are on sale rather than buying just what you need for the week. Once you have a stockpile, plan weekly meals around what you have and perishable items that are on sale.

Cut the cost of wireless service.

If you're not locked into a two-year contract with a wireless service provider, you can lower your monthly bill by switching to a smaller carrier that offers more competitive pricing. If you don't want to switch to a smaller carrier, consider opting for a plan with a lower data allotment.

Cut the cable cord — or at least trim it.

The average pay-TV bill will be $123 per month in 2015, up from $86 in 2011. So cutting your cable cord can yield quick savings. Less drastic actions: forgoing pricey premium channels and opting for the most basic package. Or you could ditch cable and still get live programming with Sling TV.

Re-shop your auto insurance.

The J.D. Power 2015 U.S. Insurance Shopping Study found that consumers who shopped for better auto insurance rates and switched insurers saved an average of $388 on their annual premium. You can get quotes and compare offers from several insurers at the Zebra, InsuranceQuotes.com and CarInsurance.com.

Slash your electric bill.

You can lower your heating and cooling costs by using a programmable thermostat to automatically adjust the temperature in your house when you're away from home. You can reduce your bill more by unplugging energy vampires — devices such as cable TV boxes and DVD players that use electricity even when turned off.

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