Over 44 million American adults have a side hustle today, according to a survey released from the financial service company Bankrate.com.
A side hustle can range from a part-time job with another company to a hobby you'd like to make money from. Author and speaker Chris Guillebeau wants to help professionals figure out how to turn their skills and passions into a business.
"There is a debate about what [side hustle] actually means," Guillebeau tells CNBC Make It. "I'm trying to encourage people to not think about the gig economy like driving for Uber or working part-time because they need to."
In his book, "Side Hustle: From Idea to Income in 27 Days," he breaks down how to identify a good side hustle idea and turn it into a profitable business in four steps.
1. Generate ideas based on your current skills
Guillebeau says some of the best ideas for a side hustle come from thinking about the skills you already have.
"I think a lot of people think they need to go out and get new skills," he says. "Some people say I want to create an app and I say, 'Are you a developer?' and they will say 'No.' So, I try to help people understand that the skills they already have are enough."
After writing down your skills, Guillebeau says you can then start to build an arsenal of ideas for things you'd like to do. In his book, he outlines how week one of developing your side hustle should consist of writing down your ideas, weighing the challenges and opportunities of each and then forecasting their profitability.
2. Select your best idea
In week two, Guillebeau suggests narrowing down your ideas by taking a "Tinder for side hustles approach" to find the right one.
"You look at a lot of ideas, rejecting most of them, flirting with a few, and then — hopefully — settling in for a trial phase with the most attractive and well-rounded option," he writes in his book.
Guillebeau advises side hustlers to devote 10 percent more effort to two main areas: changing customers' lives and making more money. He warns against only considering short-term business opportunities.
"Most important is to make sure you are actually making a sustainable income from it and you feel confident that it's not something that will only last for six months or a year," he says.
To test your idea, look at other businesses in your industry to see if your side hustle is better than or different from what's already being done. From there, Guillebeau says you should think of who your ideal customer is by considering who your business is serving and the pain points you are helping them to solve.
Afterwards, write an offer letter to that ideal customer explaining how your business will change their life, why they should purchase your product or service and the estimated price for what you're offering.
3. Prepare to implement your idea
Guillebeau says week three should consist of solidifying the details that will make your side hustle ready to launch.
Sit down and finalize your price points. If you're selling a product, first figure out how much it will cost you to make the product and how much time it will take. From there, choose a markup price that will yield a profit you're comfortable with. If you're selling a service, then Guillebeau says to consider how much time it will take for you to complete the service and determine a minimum hourly income that's acceptable to you.
Next, decide on a payment system — like PayPal or invoices — that will be best for your business. Write down the process of how a customer can discover your product or service and purchase it. Be sure to consider any problems a customer might encounter when trying to do business with you and think of possible ways to solve them.
"By thinking through different problem scenarios, you may identify obvious solutions that will save time and hassle later," writes Guillebeau.
4. Launch your side hustle
It's time to launch your business.
In week four, Guillebeau says you must channel your inner Girl Scout and promote your business every chance you get. Reach out to friends and supporters in your network and ask them to help spread the word about your new service or product. If you don't have the time or resources to launch an official website yet, Guillebeau suggests setting up a Facebook page.
He also suggests implementing deals and promotions in the early phase of your business to encourage people to support you.
Launching a business in less than a month may sound scary, but Guillebeau says the best time to buckle down on your new side hustle is before you think you're ready.
"I don't want people to wait six months, eight months or however long to start their project," he says. "It may take you a while to fully get it off the ground, but it shouldn't take you longer than 27 days to launch a website or promote a product. There is no way to validate those ideas without actually doing them."
Want more side hustle inspiration? Catch the series premiere of "Staten Island Hustle," Wednesday April 11 at 10 PM ET/PT on CNBC.
Like this story? Like CNBC Make It on Facebook!
Don't miss: This 29-year-old turned her side hustle into a full-time job as a 'bridesmaid for hire'
This a revised version of a previously published post.