"If your idea can't fit on the back of an envelope, it's rubbish," Richard Branson once said. Crafting a pitch that is simple, concise, and exciting isn't as easy as it sounds. It takes creativity to tell a story that doesn't overwhelm with details but has enough content to woo investors, customers, and stakeholders. 

After spending years building and pitching your company, Stitch Fix CEO Katrina Lake, whose company went public less than one year ago, has mastered a pitch that has all of the elements of a great elevator pitch. It's a good model for your pitch.

In a recent discussion at Recode's CodeCon in Rancho Palos Verdes, California, Lake was asked to describe her company for those who aren't familiar with it. If you've used Stitch Fix, you know that it's an online personal styling service that delivers clothes to your door. But how would you describe it to someone who's never even visited the website? You wouldn't begin with the tagline: "Your partner in personal style." It's a good slogan, but it doesn't explain why the company exists or how it works-- essential components of a strong elevator pitch.

Let's analyze each sentence of Lake's two-minute response:

1. "What we're trying to do is take this element of personal shopping that used to be available to a very high-end customer--someone who knows you really well, makes selections on our behalf, and has you try things on--and we make that accessible."

A good elevator pitch offers perspective and some background. It starts with the big picture before diving into the weeds or details. In one sentence, Lake's told me that she's making a service that used to be reserved for high-end retail customers accessible to the average online shopper. And she's described, in a few words, what "high-end" shopping means.

2. "At Stitch Fix, you let us know a little bit about yourself and we will have stylists, with the help of some tools, send things directly to your home."

In one sentence, Lake explains how the process works. The "tools" are complex algorithms driven by artificial intelligence and machine learning. But that's too much detail for a short pitch. "Tools" is a specific word, but broad enough to dive in later.

3. "It's like Netflix just starts rolling exactly what you want to watch, or you go into a restaurant and, without a menu, it just brings you food."

A skilled communicator understands the power of analogy. Analogy is often used to make the abstract tangible. We think in analogy and process our world in analogy. If you can compare a new service that's unfamiliar to most people to something that most people have experienced, then do so. Here, Lake chooses an online analogy like Netflix, and a bricks and mortar analogy like a restaurant.

4. "What people really want is jeans that fit, or a shirt that looks good, or a dress to wear at a wedding. The part of the shopping experience they don't want is sifting through millions of things you can filter through and sort online. We use experts and data science combined to take the burden of discovery out of the consumer's hands and to deliver to them what they really want--clothes that make them feel their best."

Lake closes the loop on the pitch and, once again, makes the process tangible. She doesn't stick with the generic "shopping experience," which can define any retailer. Instead, she makes it concrete by referring to jeans that fit, shirts that look good, or a dress to wear for a specific occasion. She also ends the pitch with the ultimate goal or aspiration--clothes that make you feel your best. 

Lake has had practice. She started the company in 2011 and experienced her share of rejections, naysayers, and skeptics. She refined the pitch over time. Today, Stitch Fix is a $3 billion company.