Before you brave the chaos of Black Friday next week, remember that it took months, even years to get those products onto retailers' shelves.

Even though tools like 3D printing and platforms like Alibaba may speed up the process of prototyping, building hardware products remains notoriously difficult.

I asked the co-founders of Canary, the smart home security system, and Eight Sleep, the smart sleep tracker, the five most important pieces of advice for anyone who hopes to build consumer hardware.

These founders share what it took to go from bootstrapping a prototype to launching on IndieGoGo and eventually raising $41 million and $22 million in funding, respectively.

1. Open source your prototype

Before investing any time in aesthetics, packaging, or marketing you first need to prove you can build a prototype that demonstrates the utility of the product you hope to eventually build. This is called a "works like" prototype.

Works like prototypes can and should be cobbled together with existing technology. Open source products like the raspberry pi enable you to rapidly demonstrate value with off the shelf hardware, custom software and grit. This approach works well to manufacture tens of devices that can be used to persuade early backers that your vision is possible.

When you're ready to start producing hundreds of units, you'll need to take a different approach. "In order to find partners capable of scaling our production, I tore apart a dozen IP cameras to find the components and sensors used by products already on the market" said Chris Rill, co-founder and former CTO of Canary. "Those partners enabled us to deliver our first shipment of products to our IndieGoGo backers, who pledged two million dollars in pre-orders." 

2. Don't try to teach yourself

Unlike software development, hardware engineering requires too much specialized expertise that is rarely found in one person.

"Don't waste your time trying to learn every discipline or search for a unicorn with all those skills already. Instead, hire a product engineering firm with the requisite expertise" says Massimo Andreasi Bassi, co-founder and CTO of Eight Sleep. "What seems expensive in the short term will help you avoid heartache in the long term." 

Just be sure to hire a firm with relevant experience. "Electronic devices vary dramatically in complexity. Even though products may look the same when wrapped in plastic, the electronics inside can be vastly different" said Rill. "Ask about specific experience when interviewing any product design firms. Ideally, they're executing from previous successes." 

3. Hire a Program Manager

Hardware products are notoriously difficult to deliver without delays. Pebble, Jawbone and more recently  Doppler Labs all ended up delaying shipment.

So many things can and will go wrong when manufacturing hardware. Unless you've been through the process before, it's best to hire a program manager to keep track of all the moving pieces. "It's a full time job coordinating suppliers, manufacturers, and the dozen other partners" said Rill. "You'll be more prepared for the 'common' issues and have more time for the unpredictable issues that inevitably arise."

4. Negotiate in person

In the early days you will never order enough parts to secure a meaningful volume discount. So don't try to. Find other ways to persuade manufacturers to offer pricing incentives.

Even though manufacturers rely on high tech robots, it's still a relationship driven business. Instead of placing orders online or exchanging emails invest in building a personal relationship. Buy a plane ticket and introduce yourself in person to demonstrate commitment to forming a long-term partnership.

When a US-based middleman quoted $8.00 for a part, Rill experienced extreme sticker shock. After research revealed the original manufacturer, he flew to Taiwan to introduce himself in person. Over tea, he persuaded the factory's owner to reduce the unit price to $1.25. That generated 82 percent in savings from the original price quote before Canary shipped a single unit.

5. Know your dependencies

Your product does not exist in isolation. It depends on dozens of partners including suppliers, shipping carriers and retailers. Each play a critical role to ensure your product arrives fully-functional in customers' hands.

When factories go on strike, packages are lost, or components malfunction don't be caught off guard. Invest the time upfront to identify each of these dependencies and design redundancy or remediation procedures.

When some internet providers began to disable a frequency in their routers, Canary's cameras could no longer connect to the internet. That caused frustrated customers to reach out for assistance.

Canary's support team had to help customers reactivate the frequency on routers, which was not an ideal customer experience. Rill recommends "when it comes to complex critical systems like, connectivity, remember that you depend on a rapidly evolving ecosystem around you."