Starbucks lets you place an order using Alexa with the Starbucks Reorder skill. After you enable the skill, you will need to link your account. The skill will not work unless you've previously placed a mobile order with the Starbucks app on Android or iOS. It can place an order at one of the last 10 Starbucks locations you've visited in person. You can also check your account balance and switch between your five previous mobile orders.
Like all AI devices that use National Language Processing or NLP, Alexa does not understand all voices easily. But she learns to understand her people over time. She does, however, require people to speak in simple terms, with appropriate pauses, and use specific word orders. There are many times when she will say "I'm sorry, I don't know the answer to that question." More than likely, she doesn't recognize a word order or misunderstood the question.
Alexa Skills themselves are quite helpful. However, even with an updated Skills section in the Alexa app and the ability to add skills using only your voice, discovering new and useful skills is a less than desirable experience. So much so that Amazon actually created a skill called Skill Finder which, you guessed it, helps you discover new skills. Launch it by saying, "Alexa, open Skill Finder" or "Alexa, tell Skill Finder to give me the skill of the day."
For tracking your food, you can use the Track by Nutritionix skill, which lets you record your food intake using your voice, or ask for caloric values of foods. (Alexa does the latter by default.) Say things like, "Alexa, tell Food Tracker to log a cup of almond milk" or "Alexa, ask Food Tracker how many calories are in two eggs and three slices of bacon."
Warner Brothers created a choose-your-own-adventure game for Alexa called The Wayne Investigation, wherein you investigate the death of Bruce Wayne's parents, Thomas and Martha Wayne. Start the game by saying, "Alexa, open The Wayne Investigation" and follow the prompts. Each choice you make affects the outcome of the story. This is one of the best examples of a game style that suits Alexa perfectly.
If you want to do some casual research for a future trip, you can get fare estimates using the Kayak skill. You can say, "Alexa, ask Kayak where I can go for $400" or "Alexa, ask Kayak how much it costs to fly from Los Angeles to Dublin." The skill will ask for additional information and eventually provide you with a series of options and price ranges.