Want to make your summer vacation great? Travel Leaders Network of travel agents assists millions of travelers every year, planning cruises, adventures, resort getaways and everything in between for their clients around the globe.

Here's what they have to say about easing the stress of travel during this busy season.

Checking in well before heading to the airport, saves time. Airlines generally allow travelers check-in for their flight 24 hours in advance and up until a couple hours before the flight.

Travel Leaders advises travelers to opt for digital (and paper) versions of their boarding passes so that they have a backup handy on a mobile device.

It's not a good idea to cut it close at the airport. Often in summertime traffic may be heavier than usual and parking spots could be scarce. It's also likely lines at baggage counters and security will be long.

Travel Leaders notes that "there is peace of mind when there is extra wiggle room in the schedule and to arrive at the airport 75 minutes before the scheduled departure for domestic flights and three hours before international flights."

The one thing you don't want to find out when you are already at the airport is that your bags are too heavy or not the right size or weight for the overhead cabin.

Travel Leaders reminds travelers that, when preparing to pack bags, it's ideal to check in advance whether luggage meets the airline's size and weight restrictions for checked baggage and carry-ons.

Want to make your vacation extra great? Travel Leaders suggests packing a few vacation essentials in a carry-on, such as a swimsuit and a change of clothes.

"This helps if your luggage gets delayed because you can still go for a swim upon arrival or put on a fresh change of clothes. This also comes in handy for those who arrive at the resort before the room is ready. Simply lounge by the pool or beach while you wait."

TSA allows each passenger to bring one quart-size bag of liquids and gels, including toothpaste, gel deodorant and lotions through security. Each item must be 3.4 ounces or less.

Travel Leaders also notes that travelers should be aware of powders: "Excluded from the carry-on list this summer are canisters of powders larger than 12 ounces. This affects protein powder for your mid-flight energy drink or a large jar of your favorite ground coffee."

This rule applies only to international flights and does not include infant formula or medications.

If you don't want to stand in a one-hour line at security or customs, enroll in a trusted traveler program such as TSA PreCheck, Global Entry or CLEAR, says Travel Leaders.

Travelers who enroll in one of the expedited security checkpoint services spend less time in line. PreCheck members don't have to remove their shoes, belt or jacket or take their large electronic devices from their carry-ons. So not only is the security screening less cumbersome, it also saves time not having to repack items and retie shoes-which can be a hassle for a family of four.

Don't let long layovers be a drag. Gates can be crowded during the summer and an airport lounge can be a one-stop shop for food, drinks and speedy Wi-Fi access.

"Most lounges offer complimentary food and beverages, along with free wi-fi. Those perks alone are worth the value for frequent travelers," says Travel Leaders.

Get the relaxing part of your vacation underway early and book an all-inclusive resort.

"After arriving at one's destination, especially an international one, an all-inclusive resort is especially satisfying on that first day in town away from home. No need to navigate to another location for dining or worry about menu prices. An all-inclusive package alleviates some decisions when all that is top of mind is relaxing," advises Travel Leaders.

If you choose a cruise for your summer vacation, travelers can enhance the experience with a few tips from Travel Leaders.

"There are many ways to take advantage of a cruise experience. First, arrive in the port city a day before sail time. This way, even if a travel companion misses a flight connection there is no worry about missing the boat.

"Once onboard, curtail exhaustion by skipping an excursion or two. Take time to enjoy the ship with fewer people onboard while others are off exploring the port city.

"But when planning to go ashore, make sure you listen to the port talks. A lot of valuable information is relayed, as well as maps, taxi and shop information for those who choose to venture on their own."

Developing communication skills to help you ask for the basic essentials in your new destination is a great idea. Travel Leaders says that 'learning a few words in the native language of the country you are visiting will ease stress."

Start simple with "hello" or "thank you." Making an effort to communicate often brings out the kindness of strangers.

Travel Leaders also suggests downloading apps that can translate words and phrases.

You are required to show eligible ID at the airport in order to board a flight if you are over 18 years of age. Make sure you have it easily accessible and ready to hand over to TSA agents.

"It's a good idea to have color photocopies and digital copies of all important identification documents, including your passport, boarding passes, front and back of credit cards and health insurance information," Travel Leaders recommends.

It's also a good idea to have a couple of extra ID photos that are passport-size in case you need a replacement or a last-minute visa.

"Bring the email and cell phone number of your travel agent with you, and provide your travel agent with your personal contact information, as well as pertinent health and travel insurance information," says Travel Leaders.

Travel agents can be your lifeline if something goes wrong.

"Your travel agent can rearrange your itinerary should you decide to extend your trip, or if there's an emergency," notes Travel Leaders.