I've been to 35 all-inclusive resorts. I always watch out for these 7 red flags.

• I've been to 35 all-inclusive resorts and I see a lot of first-time mistakes and red flags. 
• Check what's actually included in the cost of your stay and ensure activities have safety protocols.
• Check the specialty dining restrictions and make sure the reusable cups are actually clean. 

You may already have a trip to an all-inclusive resort on the books, or perhaps you're still browsing.

Either way, you have lots to look forward to, from lazing on the beach with a cocktail in hand to trying local cuisine at the hotel's restaurants.

As a travel writer, I've stayed at almost 40 all-inclusive resorts in Mexico, the Maldives, the Caribbean, and more. Many of my stays have been dreamy, but I've also uncovered some inadequacies.

Although no resort is perfect, some have their share of red flags that can take away from your overall enjoyment. Here are the ones I look out for:

Sad-looking buffets

Love them or hate them, buffets are often a major dining feature at an all-inclusive resort — and the options should always look enticing and appetizing.

Watch out for buffets where the food isn't replenished frequently or just doesn't look fresh. Also, be on the lookout for chefs who use the same utensils for raw and cooked meat or fish, which can lead to cross-contamination.

Take a good look around before you start piling things on your plate, or stick to the à la carte restaurants if that's an option. If you're dining at a restaurant that offers both sit-down and buffet menus, remember that servers sometimes pull food straight from the buffet.

Lounge chairs that are all claimed before breakfast

At all-inclusive resorts, I've seen guests wake up early to stake their claim on the best loungers on the beach or pool deck, only to leave for breakfast and return hours later.

This is one of my biggest pet peeves, and I can't find any rhyme or reason to predict when it occurs. I've seen it at large and small resorts, those that cater to only adults versus families, and budget to luxury properties.

If you want to sleep in a bit (you're on vacation, after all), you're often out of luck.

If you show up and see rows of seats with nothing more than clipped-on towels, ask the pool attendant if the property enforces a policy of removing unattended chairs after a certain time period.

But as I've learned, unfortunately, you might need to join the fray of seat savers — or arrive late afternoon when people start trickling back to their rooms to get ready for dinner.

Cheap, poor-quality alcohol

When you make your way to the swim-up bar, take a look at the bottles on the shelf. If all you see are unrecognizable brands, you could be in for a killer hangover.

That being said, depending on where your resort is located and your booze knowledge, there might be some great locally-produced spirits that are just unfamiliar to you. Google is your friend here.

If your internet search proves what you suspected — that the resort is serving spirits below your standards — you might want to stick mostly to beer or low-ABV spritzers (wine, club soda, simple syrup, and citrus), with the occasionally fruity frozen libation thrown in.

If you want a great cocktail, seek out a bar at the hotel with top-shelf liquor — lobby bars are often a good bet, as are those located at a resort's higher-end restaurants.

Excessive upcharges

The term "all-inclusive" doesn't mean what it used to.

Although you can be sure that your accommodations and at least some food, beverage, and activities will be included, some resorts that tout a "leave your wallet at home" mentality actually offer only a bare-bones experience, with everything else requiring you to pony up.

The buffet may be included, for example, but dining at the other restaurants will require a surcharge. Even at restaurants that are part of your package, premium dishes like steak and lobster may have an extra fee.

You might also have to pay for top-shelf beverages or wines beyond the house white and red, and room service might be an additional charge.

Find out before you book what'll automatically be part of your package, then decide if that's enough of a draw for you — or if the upcharges fit into your budget and you don't mind paying them.

Huge restrictions on special dining

All-inclusive resorts may have several dining concepts — popular options include a steak house, a seafood restaurant, and a spot serving local cuisine.

But before you get too excited about restaurant hopping during your vacation, know that there are often restrictions on the number of à la carte restos you can hit: The longer your stay, the more you can try.

Also, one or more restaurants or bars may be reserved for concierge or VIP-level guests, and others may be designated as adult-only. Check the website before booking.

If you're a foodie it seems like all you'll have access to is the buffet, you might want to choose another resort.

Reusable cups at the bar that don't seem very clean

I appreciate resorts that are trying to reduce or eliminate single-use plastics. But I've also witnessed bartenders barely rinsing cups, only to stack and reuse them despite their visible lipstick and piña colada residue.

Not only is it gross, but it also makes me wonder what other shortcuts they're taking.

To avoid this unpleasant experience, bring your own refillable travel mug and ask the bartender to fill it, find a disposable cup, or order something in a bottle or can.

Activities without safety protocols in place

All-inclusive resorts offer various activities, from stand-up paddleboarding and kayaking to more adrenaline-fueled pursuits like parasailing and scuba diving.

Before heading out on or under the water, do a little auditing of the safety equipment and processes — or lack thereof. Are life jackets provided or available to every guest partaking in the activity? Are operators licensed and knowledgeable? Are you given clear instructions, including what to do if something goes wrong?

Again, online reviews can be super helpful in determining whom to book with. If safety measures seem a little loosey-goosey or if something just seems off, look elsewhere.