As a Master Crocheter, I made more money teaching crochet classes than I did from my hand crocheted items - even though I sold seemingly TONS of them. Another way to make good money with your craft is to make the model items for publications. I've only done a few model items for publication.
In the late 1980's I was able to place my quality handmade items in a museum gift shop (on consignment). I couldn't crochet fast enough to keep up with the demand for my items, as well as special orders.... That's when crocheted collars were all the rage. I also made beautiful napkin holders (I would sell them by the dozens) with matching coasters, lacy Victorian Christmas decorations, doily-like jar covers, sachets, filet crochet window valances, dresser scarves, doilies, wedding purses, and some baby/childrens items. One of the most sought after items were my original design for crocheted tea sets (cups, saucers, creamer, sugar bowl, and tea pot on a crocheted tray), which I made with #30 (very tiny) thread.
What I found out - you never get enough from selling them to pay for your time. For each thing you make, you'll get back the price for the thread/yarn involved, but you'll never get minimum wage when it comes to the time involved. So that's something to consider.
I used to work 8-hours a day as a professional knitter/crocheter, but I have paid-the-piper with arthritis in my fingers, carpal tunnel and tennis elbow now for my trouble, so I do very little serious needle work these days.