I tried my hand at full on consulting in the 90’s (yes I know I’m old, move before I hit you with my cane!) When it comes to Tech and dealing with people I’m unstoppable, but running a business taps many other skills sets that many of us don’t have developed. I had a number of customers, but I was really bad at getting billing done properly - REALLY bad. Like forgetting to bill for months bad. I discovered I need help if I want to run a business, I just don’t have the skills to do it all. It’s hard work, there is no such thing as a quick side business if you want any measure of success.
Now as to your question about ideas to pursue, the best chances are the ones that minimize your personal risk. Avoid things that require you to lay out any funds before you start. The T-shirt business sounds cool, but won’t work as well as you think. The novelty market is already saturated with web based companies, you can’t t really compete. The custom market has a lot of players in most areas, heck in my small town of 900, there are two places that do custom t-shirts, and it’s one of many services they have to offer to stay in business.
Look at business ideas that fall inside your wheel house and ideally can be started up with minimal layout. I’ve thrown this out a whole bunch of times, and it’s solid idea that works so I’ll throw it out again. Getting small/med companies online. Walk into any small business and ask them if they thought about getting a web presence. offer two packages, basic and premium.
basic = simple website, domain name, and email (set up to the device of their choice) and monthly updates to the website
Premium = basic stuff plus social media presence (twitter, facebook, pintrestest, etc - anything that applies to their business) with weekly updates on social media
charge $200 a year for basic $350 for premium. add $50 to the first year for setup on basic, $100 on premium
a hosted web service will run you at most $200 a year, it’s $10 a year for a domain name. As soon as you have two customers you are making money. For the webpages, just build from existing templates. I do this now, I spend a three hours a year on each customer outside of initial setup. ( only have a couple clients but it pays for my personal stuff) and I only have to remember to bill them once a year, so I can manage that.