1. Shop around

First, check the daily cost of a vehicle on sites like CarRentals.com and VroomVroomVroom.com as well as Expedia, Travelocity and Orbitz. Then check rates on car rental company sites. Be sure all the prices you compare include fees (including those for additional drivers) and taxes.

2. Say ‘No’ to extras

Additional insurance coverage, refueling charges, and GPS rental can sabotage car rental deals. Worse, agency staffers are trained to “up sell,” often playing on your fears about, say, not having sufficient insurance. If you own a car, get the policy information about your coverage while renting in writing from your insurance agent. Also, some credit cards automatically provide collision coverage if you pay for a rental using them. In general, those expensive refueling charges aren’t necessary. Find cheap places to tank up on Gasbuddy.com, which has a app. Other apps include the AAA’s TripTik and GasBook (99 cents on iTunes). If you have a smartphone, use Google maps instead of a GPS.

3. Book early and book compact

Booking early often gets you better car rental deals. Unless you’re traveling with lots of people or lots of luggage, reserve a less expensive compact with better fuel efficiency. Also, because compacts aren’t popular, rental companies fill their lots with bigger cars; if they run out of compacts, you might get a complimentary upgrade.

4. Know your rates

Sometimes, renting for just five days qualifies you for the lower weekly rate. Also, if you don’t really need the car on Thursday, say, except to get from the airport to your hotel, see if you can get the less expensive weekend rate by picking up the car on Friday. Finally, join loyalty programs. They are generally complimentary, you won’t have to stand in long lines at pickup and you’ll be eligible for upgrades and discounts.

5. Be mindful of pickup and drop-off procedures

Airport pickup is convenient, but it may mean paying $10 to $20 a day for airport fees. Instead, save money by collecting and returning your car in the city. At pickup, use the camera or video on your phone during an inspection. Be sure that counter personnel document any damages before you leave. Arrive early for drop-off — there can be a long wait, and if you’re late (even by just 5 minutes), the agency can legally charge you for an additional day.

Even worse than the expense of renting a car are all the little details you need to consider when signing a rental agreement. You’ve got to think about such things as how you’ll pay for gas, what you’ll need for insurance, and what rules and restrictions the rental agency demands. Our checklist of car rental do’s and don’ts will ensure your experience is a good one.

Compare rates

Compare rates on rental agency and travel websites. Be sure that any “deals” really are deals: Sometimes a rate really isn’t so great after you tally all the fees and taxes. Asking for AARP-member discounts could save you up to 20 percent, while AAA and travel loyalty programs can also trim costs. Checking coupon sites, booking compacts and avoiding “extras” like satellite radio are other ways to save. Consider collecting your car at a location other than the airport to avoid those fees. And be wary of rental agency gas tank fill-up packages; some quick math, depending on prices at the time, will help you determine whether filling up yourself is the better option.

Book early

Booking early gives you flexibility — for choice and pricing. Longer lead times mean more available cars, a broader selection and better rates. Arrive early, or at least on time, when returning a rental car. Even slight tardiness can cost you an additional day. This bit of car rental advice seems obvious, but think: Do you really need a rental car? Paying for a rental, gas and parking doesn’t make sense if you’ll spend most of your vacation lounging on a beach or exploring city streets. Consider renting only for a day or two and using public transportation and cabs the rest of the time. On the other hand, if you lease your existing family car, and you’re planning a long road trip, renting makes sense for avoiding costs associated with exceeding the lease’s annual mileage cap.

Limit insurance

It’s highly likely you are already covered for a rental car on your existing policy, but check first with your insurance agency, buying only supplemental insurance as needed. At the very least, you need good collision-and-damage waiver (CDW) insurance. Some credit cards also offer CDW when you use them to charge car rentals.

Beware of restrictions

Most, but not all, U.S. agencies allow you to cross into and drive around Canada. There might be some restrictions and insurance issues, however, so ask before heading to the Great White North. Meanwhile, down south, driving into Mexico is forbidden by American-based agencies. In addition, some agencies have restrictions on back-country driving, say, or taking cars into major metropolitan areas. Be aware of those restrictions before taking that Land Rover for a desert jaunt.

Check for damage

Walk around the car, noting any dings, scrapes or dents. Use your camera or smartphone to take pictures or video of any damage (or lack thereof). Point out damage to the rental agent and ask him or her to note it on the paperwork. If you encounter any pushback, or the damage seems extensive, request another car.

Ways to Save on Rental Cars

These tips will help you find the best possible rental rates.

1. Go beyond the big names

Check out airport-based companies like Sixt, Payless, Advantage and Fox, as well as the cheaper arms of the big three, like Dollar and Thrifty. As a condition of its merger, Hertz agreed to give up at least a dozen airport booths — and smaller companies are the likely recipients of the coveted space. That will boost the competition over prices even further.

2. Try an off-airport location

Taking a shuttle or even paying for a taxi to a rental office that’s a few miles away from the airport can mean a lower rate — 50 percent lower is common — for the same car, from the same company, for the same length of time. Many companies run complimentary shuttles from some of the major airports.

3. Look for package deals

If you’re flying or booking a hotel as well as renting a car, consider a combined deal offered by an airline or booking agency. Car rental companies can provide discounts to companies that include rental cars as part of a package, which can mean savings for you.

4. Reserve early — but check back

You’ll typically get the best prices by booking in advance. But rates can continue to fluctuate, so keep looking for better deals. (There’s no penalty for canceling and rebooking.) One website, AutoSlash.com, actually helps you do this by allowing you to plug your existing reservation into its site. It will then cycle through various available options to get you a better deal.