You're getting ready to buy a new or used car. The car you currently drive is in good enough shape and may have some value to it. Should you sell it yourself or trade it in?

Simply put, if you want the most possible money for your vehicle, you're better off selling it yourself. Potential buyers are not as well-trained in car valuation as the pros, and they're not trying to eke out every bit of a car's value for resale, so you'll likely get more money. However, this process takes time, and perhaps more effort than many people are willing to invest. In fact, some 43 percent of all car purchases in 2017 included a trade-in, according to Edmunds data.

Trade-in offers are typically less than you'd get in a private-party sale because the dealership must factor in the cost to recondition the vehicle and make a profit when it resells it. The plus for car shoppers is that trading in your car can be very convenient, far more so than finding a private-party buyer. If you follow these tips, you can get the most for your car trade-in.

1: Get Your Car's Trade-In Value

To determine if you're being offered a reasonable price on your trade-in car, you first must know what your car is worth. (People sometimes call up the car's "Kelley Blue Book" value.) We suggest you use the Edmunds car appraisal tool and look for the trade-in True Market Value® (TMV®). Read "How Much Is My Car Worth?" if you need tips on how to appraise your car. Print out the results page and take it with you when you visit car dealers. You also can pull up the trade-in value on the Edmunds smartphone app for Apple or Android devices.

It is important to accurately take stock of all the car's options and be honest about the condition. Note that only a small percentage of cars will actually be in "outstanding" condition. Most vehicles that are well-maintained will be in "clean" condition. When in doubt about the condition level, it's best to err on the side of caution.

2: Get a CarMax or Dealer Estimate

We recommend taking your vehicle to CarMax for its first appraisal. Show up early and you can get in and out in about 30 minutes. CarMax will give your vehicle a detailed inspection, along with a written appraisal that's good for up to seven days.

At this point, you can either take the CarMax offer or go to other dealerships to see if they'll make a better offer. In our experience, we've found that CarMax offers more for a trade-in.

But if you are "upside down" or "underwater" on your auto loan — meaning that you owe more than the vehicle is worth — you'll have to pay CarMax the difference between what you owe and what the vehicle appraised for. If you're not prepared to pay the difference on your car loan, trading in at a dealership might be a better option.

Don't have a CarMax nearby? Call the used-car manager of your local dealership to set up an appointment for an appraisal on your vehicle. Timing is critical here. Whereas CarMax might have at least two appraisers, most dealerships will only have one person appraising potential trade-ins. If you show up on a Saturday afternoon, you could be waiting for a while. Try to schedule the appraisal for a weekday morning when things are less hectic.

Keep in mind that the trade-in price you're offered at the dealership (or CarMax, for that matter) can vary depending on a number of factors, including the car's condition, the dealer's current inventory and the likelihood the car will sell. There may also be special promotions around trade-ins. More about that later.

If you have a CarMax appraisal, you will already have a reference point to compare the dealer's offer. If not, you may want to try to get two dealers' appraisals.

Here's a good strategy you could try: Take your car to a dealer other than one that sells your car's brand. For example, take your Toyota Camry to a Chevrolet dealer. This way, your car won't be competing with six other Camrys on the lot. A non-Toyota dealer, which is very likely to sell used cars of other brands, may offer you more for the Camry than the Toyota dealer would.

3: Negotiate or Close the Deal

Once you have appraisals, you have a couple of options. You can either take one of the offers you have or negotiate for a better price (not an option for CarMax). If the CarMax offer is the highest, sell it there. If you have your paperwork in order, you could be done in 30 to 40 minutes. But if you are upside down on the car and need to fold the loan balance into your next car's financing, the dealership is the best place to do so.

If you're deciding between two dealerships with similar offers, you may want to lean toward the one at which you intend to buy your car. This tactic gives you some leverage since you're giving the dealership business on both the trade-in and the car purchase.

The first trade-in offer at a dealership is often on the low end, so there's room to negotiate. Say something like this: "I intend on buying a car from you today, so if you can improve on the trade-in price, I'd love to give you my business."

Another strategy is to use Edmunds TMV as a guide. Say something like this: "I've done some research on this car and it looks like the Edmunds trade-in value is slightly higher than your offer. I realize it's an average, but can you beat this price?"

Sometimes this strategy will work. Sometimes it won't. But if you've solicited more than one offer, you should have some options. If you keep getting the same offers for your vehicle and none of them are what you had in mind, you may have to temper your expectations. This may very well be the market value of the car, no matter what you think it should be worth.

At this point, you can either take what you're being offered or try to sell the car yourself. Some people may even choose to keep the car as a daily driver rather than pile miles on a new car.

You may be able to make the timing work to your advantage. Target the end of the month, when the dealer may be more willing to give you an attractive offer. You also can look for special promotions, such as when the dealership may offer extra cash as part of a trade-in event that's meant to beef up the used-car inventory.

When you're car shopping, keep negotiations for the new car and your trade-in separate. The trade-in amount should be written in the contract as a credit against the purchase price of the car. In some states, you only pay sales tax on the difference between the new car and the trade-in. This means that on top of what you receive for your trade-in, you are paying less sales tax on your new car. This tax advantage is a net savings for you and could make you decide that trading in is worth it. Details are in our story "What New-Car Fees Should You Pay?"

Common Trade-In Mistakes

There are some common mistakes that people make when they're trading in a car. Here are some and how to avoid them:

Bringing a freshly cleaned car: There's no better way to spot a person who will be buying a car that day than to look for someone who arrives with a sparkling-clean car. You might be thinking, "Don't you want the car to be clean so it can make a good impression?" The truth is a little bit of dirt won't change the value of the car. That's not to say you should bring in a car with a bunch of fast-food bags and soda cans strewn about, but don't feel the need to have the car detailed beforehand. This way, you can play your cards close to the vest about whether you really intend to buy that day.

Repairing the car: People sometimes try to fix dents on their cars or throw on a new set of tires, thinking it will substantially add to the value of their trade-in. This seldom works. The dealer can usually fix flaws and put on new tires for substantially less than you can.

Overestimating the value: People tend to get sentimentally attached to their cars and often think they're worth more than they actually are. They look for the highest car value on an appraisal site for their vehicle and treat it as though it were set in stone. But appraisals are averages, meaning some dealers offer people less and others more. Rather than fighting over the car's value, your efforts might be better spent on negotiating the new car price.

Hiding information: Some shoppers fib, claiming to have a high trade-in offer in the hopes the dealer might try to beat it. This rarely works in car deals. An experienced appraiser will either see right through the inflated offer or call the bluff by asking to see the estimate in writing. If your offer is for real, display it proudly. This is where the CarMax in-writing offer comes in handy.

Also, some shoppers wait until the last minute to mention that they have a trade-in as part of the car-buying deal. This is one of the top car buying myths. It's best to be up front about the trade-in from the very beginning.

If you follow these steps and sidestep the common pitfalls, the trade-in process will run smoothly. The key is to know what your car is worth, shop around, and be realistic about the offers you get.