I absolutely LOVE affiliate marketing. Affiliate marketing can feel quite passive and it makes location independence and traveling full-time much more enjoyable. You can create just one blog post or social media post, and potentially earn money from it years down the line, as long as you maintain it and keep generating traffic to it. With affiliate marketing, I can enjoy life more and know that I am still able to earn a great living promoting products that I use and enjoy.
I have not personally done this but I would like to eventually. If you are artistic you could make artwork or handmade good such as ornaments, wallets, or jewlery and sell them online. Something that I personally would like to do is design T-shirts and sell them. Shop for anything from creative people everywhere is a great site and I have bought many things from them. If you make quality products and get your name out through Facebook or other social media you could get a substantial business going.