I'm making and selling a couple of LED pin badges on my site https://hortus.dev . I wrote about my experience doing these last year (previous hn post here: https://news.ycombinator.com/item?id=38904255 ) and since then it has really taken off! Not enough to live off, but certainly enough to sustain itself and fund some more projects in the future. I never expected it to turn into anything more serious than a novelty and I've learned a tonne about running a small business as a result. I'm really looking forward to (hopefully) learning how to grow this into something bigger over 2025!