Most people know that they should try to negotiate a higher salary or a better deal on a car, but you may not whip out your haggling skills on everyday purchases. And that's probably a mistake, according to Chelsea Fagan from The Financial Diet. In this video spotted by Digg, Fagan shares some tips and tricks for getting the best deal, and making sure you aren't letting discounts pass you by.

She suggests letting go of the stigma of trying to haggle, and making sure to ask for discounts and look for deals on medical bills, subscription services, your rent, your insurance plan, credit card fees, furniture costs, and work benefits.

Here's how:

Check your medical bills carefully, because according to Fagan, somewhere around 30 to 40 percent of medical bills contain errors, so the chances of you finding a mistake are way higher than you might think. If you can't afford your bill, call your doctor's office and ask if there's anything they can do to help, like lowering the cost or setting up a payment plan. Make sure to call as soon as possible, though, before the bill goes to a debt collector.

Next, you should know that threatening to cancel your cell phone service or newspaper subscription can be highly effective. Subscription services will often give you a discount if you're thinking about leaving.

When it comes to rent, you may think there isn't wiggle room. But it can cost landlords significant money, time, and hassle to replace a tenant, and you should use that to your advantage when it comes time to renew your lease. It may not work in super-hot real estate markets, but if you're a good tenant, your landlord probably wants you to stick around.

Insurance costs may also seem impossible to negotiate, but month-to-month premiums and costs aren't as fixed as you might think, especially when it comes to car insurance. Even if they can't lower your bills during negotiation, you might be able to get benefits and perks that weren't originally included.

Make sure you're getting the best deal you can on your credit card, too. You can sometimes get your annual credit card fee waived or receive a higher credit limit just by asking, so don't be shy.

If you're buying something major for your home like a new washer-dryer combo or a full living room set, know that many stores will negotiate with you over big purchases. If you go shopping at the end of the month, for instance, sales staff might have a monthly sales goal they're trying to hit, and might be more willing to knock off a portion of the price just to make the sale.

And last, when it comes time to ask for that raise, don't stick to just demanding a higher paycheck. Vacation time, sick leave, retirement plans, and other salary benefits are all negotiable. If you can't get a higher salary from your boss, you might be able to get more vacation time or flexible work hours.

Fagan recommends that no matter what you're trying to haggle over, you're better off talking to a human. That means calling up your doctor's office, your cell phone carrier, or anyone else you're trying to negotiate with and asking for a customer service representative, instead of dealing with bills online or through the mail. Sometimes, these customer service workers might have some allowances they're allowed to give out, or in the case of shopping, a retail employee might have sales goals or make commissions, so they're incentivized to help you out.

Let Fagan break it down for you further in the video below.

[h/t Digg]