“When you hear people are really unhappy on a ship, they picked the wrong cruise line,” says cruise expert Carolyn Spencer Brown. (iStock )

First-time cruisers have a lot to wrap their heads around. There are hundreds of cruise lines out there, and sifting through the options — like the themes (“The Walking Dead” or “Oprah”?) destinations (Caribbean, Alaska, Mediterranean, Asia?) and even ship sizes (travel on the largest cruise ship in the world!) — can be overwhelming.

But here’s a little secret: Even cruise experts rely on travel agents to find the right fit. Carolyn Spencer Brown, who has been writing about cruises for nearly two decades, first as a staff travel writer at The Washington Post and now as editor-at-large at CruiseCritic.com, an all-encompassing review site and online community, estimates that she’s been on more than 300 cruises and she still depends on her travel agent to help book the right one. “I can’t imagine why anyone wouldn’t, because it takes all the hassle out,” she says. And what are cruises about, if not avoiding hassle?

Whether you’re a newbie or an aficionado, Spencer Brown has some useful insights on choosing the right cruise and other issues to consider before you embark.

Determine your travel style and what you're looking for before booking: Spencer Brown says the key is to find a cruise that's a good match for your vacation expectations. There are cruises for fitness fanatics, partyers, foodies, comic lovers, spring breakers, seniors and just about anything else you could imagine, so choose wisely. "If you want to be up late and party at night and you pick a cruise line where everyone's in bed by 9:30, you're not going to have a good time," she says. "When you hear people are really unhappy on a ship, they picked the wrong cruise line."

Don't be fooled by cruise or cruiser stereotypes: Regardless of the perceptions of cruising, the trip is what you make of it. Spencer Brown ticks off the assumptions people make about cruises: The cabins are all tiny and balconies are prohibitively expensive; the food is mediocre and all-you-can-eat; all cruise ships are pretty much the same. Cruises have evolved over the years, and you can find gorgeous, spacious cabins (for an additional fee); balconies are less expensive than you might think; excellent cuisine and wine are now part of the cruising lifestyle; and there is incredible variety to cruises, with transoceanic options, river cruises, luxury lines, expedition cruises (to the Galapagos or the Arctic) and more.

Always arrive a day early: You don't want to miss your cruise because of a travel snag, such as weather or a missed flight. Plan ahead so that you're there well in advance of embarking. "If you can, book a hotel in a port city where you can watch your ship come in the next morning. That's really fun," Spencer Brown says. And just to be safe, she recommends buying insurance, to protect you if something does come up.

Plan ahead to manage seasickness: If seasickness is a concern, Spencer Brown suggests starting out with a river cruise, because there's land on both sides and you're not dealing with the motion of an open sea. As someone who gets motion sick herself, she stocks up on Bonine, a chewable tablet that she says doesn't make her drowsy.

Know that introverts can cruise, too: But they should consider their personality when selecting a cabin. Those who will need quiet time and space may want to spend for a larger room and maybe a balcony, so they're comfortable when they retreat and recharge. If you don't expect to spend much time in your room, go ahead and get the least-expensive option.

Take charge of your land (and sea) adventures: Don't limit your options at port to the shore excursion menu shared by the cruise, Spencer Brown says. There's no need to board a giant bus or stick with the crowd. Many port cities have boutique travel agencies that can plan more-personalized trips. (If you book the cruise through a travel agent, they can help with that.) Another option is to plan an outing with others on the cruise and go off on your own. (Cruise Critic has a section, Roll Calls, in which cruisegoers can plan such things). Another idea while at port: Stay on the ship. When the crowds are away, you'll have an entirely different experience. "You don't have to wait in line for anything," Spencer Brown says. "The waterslides are empty. At the spa, you have your choice of times and treatments. You can have a nice, long, leisurely lunch. You get a chair at the pool. You get great service if you want drinks. It's so lovely to be on a ship when there's nobody else on it."

Pack wisely and leave room in the suitcase: Make sure you've saved some room in your bags for souvenirs, says Spencer Brown, who adds that she has needed to buy new suitcases on trips to accommodate her new finds. She says her rule of thumb, which she admits she often fails to follow, is to lay out everything that you think you want to take and then pack only half of it. At sea as on land, be sure and pack comfortable shoes — you will be walking more than you expect — and don't forget to bring chargers for your electronics.

If you're traveling with kids, visit the kids club right away: For families, a cruise is like a camp where children get the chance to meet friends from around the world. Just be aware that friendships and cliques can form quickly, Spencer Brown says, and it's important to get in early. "The first day you're on board, go right to the kids club and sign up and go to the first night's events, because that's when the bonds get formed," she says. She says she took her goddaughter on a cruise and they missed the first night's activities. It was a big mistake. "By the second day she wasn't comfortable because everybody else had paired off," she says.

Use technology to make advance plans: It used to be that the first day on a cruise was spent waiting in line to make reservations at spas and restaurants, Spencer Brown says. Today, technology allows you to book in advance, so you can reserve a massage and a blowout weeks before and relax when you get on the ship. "Don't pre-book yourself to the nth degree, but you want to make sure you get the stuff you really want," she says.

Spencer Brown says that a first cruise often serves as a gateway, a secret handshake, a key to an unexpected world. And, in her case, the fascination keeps building. “There’s still a magic to it,” she says. “I think that’s what you never understand until you’ve done it. It’s like a club, and then once you’ve done it, you get it.”

Silver is a writer based in Chicago. Find her on Twitter: @K8Silver.

More from Travel:

The bottom line on cruises

Hate travel planning? Take a surprise vacation!

Cruising Royal Caribbean's mega-ship — at times a little too mega