You might be hoping to take your career in a new direction or just want some extra cash for life’s little luxuries – either way, a side hustle is just what you need. But how do you get one quickly and easily, make money and have fun along the way?

Side hustles are all the rage. In a study, Henley Business School found that one in four of us have one. I turned my lifelong passion into one, spoke to people who did the same and wrote a book revealing the secrets of side-hustle success. Here are the five rules I learnt along the way. Use these to boost your bank balance and find fulfilment in your life – right now.

Working on something you enjoy means you’re more likely to start and keep going. Don’t begin with an ambition to make a million – find something that matters to you first and will make your life better now, such as figuring out how to upcycle your designer gear to keep on trend. Don’t worry if you’ve not found your passion project yet; going out into the world and exploring opportunities will engage your brain’s seeking system. Getting curious will release a hit of happy-making dopamine as you figure out what to work on. As you get stuck in, your interest will deepen, and you build the motivation to continue.

People spend on average one day a week working on their side hustles. That kind of commitment is enough to make most of us quit before we’ve begun. So, start small and lower the stakes to overcome your fear. Go in small steps. Squeeze in a little each day at a regular time and soon it will become a habit as regular as brushing your teeth, or you might prefer spontaneity to maximise time gifted by delayed trains and cancelled dates. Time blocking is your classic productivity hack – schedule in hustle-appointments each week, or go for a full-out binge in the future where you dive deep. You’ll be surprised what you can achieve, even when you’re feeling tired and uninspired.

Many people come across ideas for new businesses in their existing jobs, but don’t start up on your boss’ time or premises because contractually they own your idea. Keep it separate, but that doesn’t mean you must keep it a secret. Working on a side business boosts your skills and experience, which can benefit your current job prospects. While I was working in publishing, I told my boss about my side hustle Prolifiko, a digital coach for writing. The skills I’d gained bagged me a promotion, with more money, and I managed to reduce my hours so I could work on both.

The ultimate test of your idea is whether people will pay for it, so “sell” something as soon as you can. For example, if you have an idea for a new gadget that’s going to revolutionise the market, don’t build the product before you gauge demand. Build a website, ask people to join a waiting list, sell an idea. Design online ads to track how many people click on them; run a crowdfunding campaign or take deposits. You’re looking for commitment from people to figure out if you’re on to something.

Nobody builds a business alone, which is why side hustles are great for your wellbeing. Researchers have found that 70 per cent of our personal happiness comes from other people, so get social. Involve your family and friends in the early stages, surround yourself with supportive people who are on a similar journey, tap into the expertise in your network of peers and co-workers, and connect with early customers to build a community of fans who champion your idea. Relationships will help you and your business thrive.