Summarize the following:
You should view your side business as a laboratory for your main career.  In other words, whenever possible – and especially if your side business is related to your main career – use your side business as a forum to try new strategies, projects, or techniques. For instance, if your main career involves designing sets for films and you take up a side business designing set pieces for the theatre, try out some new strategies that you might not try at your main job. If your side business is more tangential to your main career, look at general skills or strategies that you could bring to your main career.  For instance, if your main career is running your car washing business and your side business is a hot dog stand, both will require advertising.  You might try to use a more robust digital marketing strategy to promote your hot dog stand, then use the lessons you learned to better promote your car wash. This website will be used to explain to people your services, and you can also showcase your work along with testimonials. Create profiles on relevant social networks like LinkedIn, Facebook, and Instagram. You can connect with potential customers within these networks, and also potentially find partners and other opportunities. If your side business is in a field related to your main career, you could advance your main career by referring clients from your side business.  For example, if your main career is in marketing and your side business involves drafting write-ups of new products, you could suggest to your client that they hire you (or your marketing firm more generally) to develop the new product’s advertising campaign.  You could, of course, also use your side business to develop new contacts in your main career even if the two are not closely allied, but it will be more difficult, and happen only in cases of extremely good luck. For instance, if your main career is running a dry cleaning business and your side business is running an art dealership, the two lines of work have little in common.  But it is possible that you might encounter a customer at your dry cleaning business who, in conversation, mentions that they are in the market for art.  At this point, you could suggest to the customer that they purchase some from you. In your side business, institute systems to collect feedback about your performance or work.  The more closely your side business aligns with your main career, the more valuable this feedback will be. For instance, if your main career is teaching English and you take on a side business working as an English tutor, you could ask the students you tutor to fill out a detailed evaluation about what they liked or didn’t like in their lesson, then incorporate that feedback into your primary teaching career. If your side business is less directly related to your main career, look for feedback that is more broadly transferable.  For example, if your side business is selling cupcakes and your main career is selling cars, both involve communicating with prospective customers.  You could ask customers at your cupcake business what part of your sales pitch drew them in, then apply that feedback to your role as a car salesman. If you found that feedback really benefited your side business, you might work to implement a more robust feedback system in your main career. With a side business, you will probably be taking more chances than you do in your main career.  These greater risks hold potentially greater rewards, but they also have greater potential for failure.  But even if your side business doesn’t work out or goes through a rough patch, you can advance your career by learning from these mistakes and failures. For instance, perhaps the company you work for in your main career wishes to develop a commercial space in the same complex that your side business was/is located in.  If you’ve had a bad experience with that space because it was too far from other businesses, you could save your company a lot of trouble by advising them about the shortcomings of the space.

Summary:
Try new ideas at your side business that relate directly to your main career. Try new ideas at your side business that relate tangentially to your main career. Create a website so that you have a hub for you to market your side business. Develop new contacts. Seek highly relevant feedback. Seek generally useful feedback. Learn to see failures as opportunities.