Our goal is to build and test your prototype as fast as possible. By shortening the feedback loop between building and testing, we can iterate far faster. This is crucial for learning as much as possible in the shortest time.

A prototype doesn't need to be complex. Even if your ultimate goal is to build a fancy website or app, you don't actually need to write any code to validate your idea.

When you're prototyping, get creative! Try to identify exactly what the core of your product is, and think of ways to test whether it works in the simplest possible way.

Let's imagine your product idea is for a new kind of hardware and software device to help visually impaired users navigate their homes. Geolocation and proximity sensors would identify the user's location and a vibrating belt would tell them the direction they need to move in. Building a 'real' version of this product would be very expensive and time-consuming.

But there's a simpler way. You can plan and prototype your idea in 30 minutes, without actually needing visually impaired users to test with too. During a prototyping exercise, we experimented with a very simple 'prototype' of this product: we blindfolded one of our team members and faked the product by tapping on his waist to simulate the vibrations of the belt. It's an incredibly simple setup that lets you carry out basic initial tests of a product idea and get immediate feedback.

In another prototyping experiment, we were looking for ways to help increase awareness of the needs of refugees arriving in Berlin. We had several different ideas for how an app could help achieve this, but had to face a challenging language barrier and very limited time. A hacked together cardboard prototype was a much smarter way to tackle the problem and get rapid feedback.

So, we built a very rough and simplified prototype of the app and took it to the streets to gather feedback as fast as possible. As you can see, this is a million miles away from what a final product might look like, but it was the right tool for the job at this point of the process.

Another example, this time from a real company. Mike Matousek, who founded Flashnotes.com, a study guide and crib notes marketplace, validated his initial product idea using a simple 'offline' method:

"The idea for Flashnotes.com was sparked when I was a junior at Kent State University. I started creating these detailed study guides for our exams and sold my final exam guides for $10 a piece. Not only did they sell, I was literally hunted down on campus by more and more of my classmates -- easily making over $1,000. After this initial interest, I knew I was onto something and had my friends test out the idea of selling study material in their own classes."

If you're not entirely familiar with prototyping and want to learn more before jumping in, check out these resources:

• Content-First Prototyping by Andy Fitzgerald
• The Skeptic's Guide to Low-Fidelity Prototyping by Laura Busche
• Prototyping for Better Products, Stronger Teams and Happier Clients by Scott Hurff
• UX Playbook by Hanno