I’ve owned several small businesses that started out on the side, I currently have a finish carpentry company as my main income that started that way.
IMO, it’s a great way to get things going if your desire is to work for yourself and you aren’t able to “make the jump” due to needing an immediate paycheck. Get it going on the side, when it starts taking off switch over.
As my son is now a year and a half, I am more and more hating the concept of trading my time for money, and working to get away from that. I’d much rather own a business that sells a product online and have a company fulfill the orders, write an e-book, buy another rental property, etc.
After all, the goal is to have enough money to be able to use your time off more effectively, not just to fill every moment of your day working.
There are 2 ways I would go if I were looking for a more traditional “side hustle.” If you have limited funds to invest, go buy a commercial grade pressure washer for $1,000 and get some business cards made up. You should be able to make $100-$300 pretty easily on a Saturday morning and be back home before lunch. Any days you don’t want to work you don’t have to. If it goes well you can get a college kid or 2 working for you and just have to deal with the customers.
If you’ve got a decent bit of money to invest or assets to leverage, I’d buy a lot or land in a somewhat affordable but accessible location, put a fence and some cameras up, and charge people to park boats, RV’s and trailers there. Again, if it goes well you can hire a college kid to wash vehicles, keep batteries charged and tires aired up.