Former employees reveal the best and worst things to get at Starbucks

"Most people make the mistake of paying more for shots of espresso in hopes of getting a big caffeine kick," Trang Pham told Insider, adding that a cup of regular coffee contains much more caffeine.

According to Starbucks' beverage information, one shot of espresso contains about 75 milligrams of caffeine, but a small Pike Place medium roast contains 235 milligrams of caffeine.

The pastries and desserts at Starbucks all pair well with coffee, but Adrienne Powers, a former barista, told Insider said her favorite snack is the banana-nut bread.

"The key to ordering a good pastry at Starbucks is to always ask for it warmed," Powers said. "The banana-nut bread tastes homemade when it is heated through."

Starbucks' blonde espresso is a lighter take on its classic roast, and Powers said it pairs very well with vanilla-flavored drinks.

"There's just something about the less intense flavor of the blonde roast that really makes vanilla-based drinks sing," Powers said. "I love to have mine in a vanilla latte with an extra pump of syrup."

Powers told Insider that the chain's hot or iced brewed coffee is actually a great value if you have the Starbucks card or the mobile app.

"The beans are actually pretty high-quality, and if you take advantage of the free refills, you might even save money compared to lower-cost coffee shops," Powers said.

To qualify for free refills, you must use a registered Starbucks card or the company's app to buy your drink. Only select beverages (hot or iced coffee, cold-brew coffee, and hot or iced tea) qualify.

Powers told Insider that the chain's hot tea is also worth trying.

"Our hot tea usually comes in a large mug that gives you plenty to sip on, and hot tea qualifies for free refills if you don't take it to go. Plus, it's high-quality," Powers said.

Since Starbucks doesn't give free refills for any drinks taken out of the store, sticking around for a free top-up also means you're getting more for your money.

If you're looking for the ultimate way to make every penny count at Starbucks, Becky Beach, a blogger and former barista, suggested splitting one large coffee into smaller portions.

"The best deal at Starbucks is to purchase a venti coffee of any type and then ask for two or three tall-size glasses," Beach said. "You can then pour it into the glasses so that everyone gets a small coffee that's a lot cheaper than buying them separately."

To be a bit more eco-conscious, have each member of your group bring their own reusable cup.

Pham told Insider that ordering a hot chocolate at Starbucks is a waste of money.

"You're paying $4 or more for a cup of milk and some chocolate sauce, which is the same sauce we use to make mochas," Pham said.

Instead, you may want to try ordering a sweet specialty drink with more ingredients, like a Frappuccino, or even a cake pop.

Buying a small drink at Starbucks may help you save money in the short term, but if you find yourself going back for seconds, bumping up your cup size may be more economical in the long run.

"Everyone should skip buying a tall size, because the grande and venti sizes are a better value," Beach said.

A tall beverage is 12 ounces, whereas a grande drink is 16 ounces and a venti drink is 24 ounces for cold drinks and 20 ounces for hot.

For just a few cents more, you can dramatically increase the amount of coffee or tea you get.

The coffeehouse chain offers a selection of sandwiches and wraps, but Beach said they aren't made in-house.

"The sandwiches at Starbucks aren't made from scratch at Starbucks," Beach said. "They're actually shipped from an outside source."

This may not be too surprising, since Starbucks' specialty is coffee — but if you're looking for a fresh sandwich, you may want to visit a chain that specializes in them.

• Read more:
• Starbucks employees and regulars reveal their 40 favorite foods and drinks from the chain
• I tried the signature roast at 4 coffee chains, and there's only one I would never order again
• Inside the world's biggest Starbucks, a magical 'coffee theme park' with five floors
• Disneyland's hidden Starbucks sells special cups, treats, and villain-themed drinks. Here's what it's like inside.