There's more to booking a cruise than picking your travel dates. Here's what to know.

Cruises could be considered one-stop shopping for travelers. With accommodations, transportation, food and entertainment all in one, they can help take the complications out of vacation planning.

But there’s more to booking a cruise than first-time passengers may realize.

From the wide range of lines to add-ons like drink packages and excursions that often cost extra, guests can face numerous decisions throughout the process. “There's like a pretty huge difference in booking a hotel upfront versus a cruise line,” said Andy Knowles, a luxury travel adviser affiliated with Fora Travel.

How far in advance should I book?

Booking well in advance will generally yield better rates, but travelers may also be able to find last-minute bargains if cruise lines are looking to fill space (click here for USA TODAY’s guide to finding cruise deals).

“I'd say most of my clients are booking at least six months out in advance, if not more,” said Knowles.

Should I use a travel agent to book a cruise?

You can book a cruise without a travel agent, but there are some advantages to using one.

Alyssa Griffin, who makes videos about cruising with her husband, Cullen, on their YouTube channel, Griff & Alyssa, said they began working with an agent about five years ago.

“I don’t know why we didn’t get a travel agent sooner,” said Griffin, who has been on “at least” 60 cruises (she also worked as a travel agent briefly from 2018 to 2019).

Initially, she enjoyed coordinating trips on her own and found it easy, but she said consulting an agent “takes the stress out of planning, and they can help offer suggestions and things that you wouldn't necessarily think about.”

They can assist clients with determining which line, ship and destination may be the best fit. And if travelers run into an issue or have a question, their agent can handle it for them – a nice benefit given potentially long customer service phone line wait times.

“They can also get some cool perks, like onboard credit or some will put a bottle of wine or chocolate-covered strawberries in your room,” she added. Most also don’t charge clients for their services as they earn commission from cruise lines.

Knowles encouraged travelers to use an adviser who is an expert in the type of trip they are planning, whether a family vacation or a romantic getaway.

Many cruise lines also have in-house vacation planners who can help prospective guests navigate the booking process. Travelers may be able to find cheap rates on third-party booking sites (though some customers using those have had to jump through hoops when problems arise).

Should I book my flights through a cruise line?

Packages that bundle flights with a cruise are sometimes “very enticing and worth it,” according to Knowles, but they can come with some limitations. “I will say for the majority of cruise lines that you're booking flights through their platform, it just adds that third-party element that sometimes removes things from your control,” he said.

If travelers need to make changes, for instance, he said they would have to go through the cruise line. And while they may be able to list their general preferences, it’s not as easy to choose the exact seat they want on the plane.

Are cruises all inclusive?

That depends. Cruise line fares do include items that are often sold a la carte on land, and you can technically go an entire sailing without paying much more than the ticket price.

But many extras are not part of base fares on mainstream brands, ranging from alcoholic drinks to laundry, so you can rack up quite a few additional charges depending on your priorities. That's where packages come in handy, and higher stateroom categories often include more perks.

Luxury and river cruise lines also tend to bundle more in their base fares, though policies vary.

Do I need restaurant reservations?

Not necessarily. Mainstream cruise lines historically offered an early or late seating in their dining rooms, but many have introduced flexible mealtimes in recent years and often have a number of casual walk-up venues open for dinner as well. Some lines don’t have traditional dining rooms at all.

But if you want to eat at specialty restaurants, which typically come at an extra charge, you’ll likely want reservations. Passengers may be able to make a last-minute booking, but it’s worth doing before the cruise.

“I always recommend booking those ahead of time just to have something locked in,” Knowles said. Reservations typically open 30 to 60 days before departure.

If guests change their mind, it’s fairly simple to make changes “so you’re not necessarily locked into one spot.” They can typically do so via the cruise line’s app.

The newer, the better: What to know about taking a cruise with a mobility device

When should I book excursions?

The same goes for excursions. “I always point folks towards, if there’s one specific tour that (clients are) like, ‘This is something that we absolutely want and need to do,’ that it's always best to book that as far out as you can, just to make sure that you have it available,” Knowles said.

That said, cruise lines typically offer “a pretty large handful of experiences in each location,” and he hasn’t had any clients board to find all the excursions sold out.

Are tips included in my cruise fare?

Mainstream cruise lines charge passengers for gratuities on a per person, per day basis. The cost is automatically added to their onboard account, and passengers can generally adjust them before disembarking.

Passengers can also pay their gratuities in advance. Many higher-end lines include tips in the fare automatically.

Should I prepay for extras?

Guests can buy add-ons like Wi-Fi or drink packages during the cruise, but they may be sold at a cheaper rate ahead of time. Knowles said there is typically “going to be some incentive to booking beforehand.”

“So, if you were booking a bar package, something that might be $250 on board, you'll pay maybe $200 up front for,” he said. If you know you want to book one at some point, he recommended pulling the trigger sooner than later.

Griffin echoed that, and said the convenience is also nice. “I am one to just want to get on the ship and not worry about how much money I’m spending once I get there,” she said. “So, if you've already established all those things ahead of time, it feels more like an all-inclusive vacation.”

Nathan Diller is a consumer travel reporter for USA TODAY based in Nashville. You can reach him at ndiller@usatoday.com.

This article originally appeared on USA TODAY: Should I use a travel agent to book a cruise? What to know