While my adventure is a hometead style farm vs a commercial enterprise, it still needs to bring in enough money to support our family. I've kicked around a number of ideas, trying some of them. Some work. Some did not. Unlike a commercial farm, I am diversified. Very diversified. And I try to remain really flexible.
Ideas: (I'm not going to get involved with the legal issues here. The government has all sorts of regulations when it comes to selling and trading farm products.)
Coffee. Trees grow very well in my area. I can use my shady, wooded areas for coffee. This is a nice crop for a homestead farm for a number of reasons. The picking extends over months and the timing isn't super critical. So it's easy to fit into one's work schedule. Coffee can be sold to other producers in the cherry, parchment, or green bean stage. Or you could roast it then sell it retail at framers markets or via the Internet. Even a small grower can find someone to buy their coffee, assuming you did it right and have nice coffee. And as a bonus, you have grown your own! No need to buy it. And you have coffee you can use for trading,
Macnuts. Trees grow great in my area, but take several years before they produce. But why wait? Get to know other people who have trees but don't harvest the nuts. I've found plenty, more than I have time to pick. I use to hand process nuts in a very simple but time consuming way. Now that I have a small husker/cracker, I can process a lot faster. Good quality, fresh, dehydrated macnuts sell easily. Same for macnut oil.
Fruit. All sorts of fruits grow here. Selling it is a bit of a challenge because lots of other people also grow it. The sales are there but you need to identify your customers and cater to them. Some fruits sell good as dehydrated pieces, such as pineapple, coconut, and banana. Some sell as juice.
Veggies. Chemical free veggies sell here quite well. So growing chem-free is something to consider doing. Plus veggies are good for trading.
Eggs. This is easy to do on a homestead farm. If you need two hens for your family, then feeding a few more isn't a burden. Those extra eggs are good for selling or trading.
Honey. Up until recently, honey was an easy enterprise and an easy seller. But the world has changed here. Keeping bees now takes a lot of attention. There are many failures. Honey still sells good, but it will cost you a lot more time and money to get it.
Milk. I don't have enough milk to consider selling or trading it, but it's an idea to explore. There are plenty of people here who are willing to go halfies with you on a goat. Plus you could always try your hand at cheese. Non-homogenized milk is in demand, once you identify the interested parties. Milk is an underground product, courtesy of our government. But then, so is much of the stuff sold by small producers (eggs, meat, honey, fruit juice, etc).
Meat. There is a good market here for local meats...chicken, rabbit, lamb, and beef.
Livestock. Though not a strong market, one can usually sell excess livestock. I bottle feed my lambs, making them far easier to sell.
Plants. Certain trees are fairly easy to grow and have some resale value. This takes a bit of researching. A few people bring banana trees and fruit tree seedlings to the local farmers market. I've also seen various palm trees for sale. Seedlings of veggies and flowering plants are another option. With the increased interest in gardening, they tend to sell.
Crafts. This is a wide open field. Lots of products from the farm can be used in crafting. Some sales will target locals, others will target tourists. Things I've seen include gourd art, wood carvings, jewelry, cups and bowls, interior decorations, picture frames, tables and other furniture, wall hooks, woven hats and bowls, leis, flower arrangements, garden decorations, fences and trellises. The list is as long as people's imagination.
Compost. Gardeners eagerly buy good compost. Other options are wood ash, bonemeal, manures, worms.
Firewood. Yes, there is a market for firewood in Hawaii.
Logs. Ohio logs of building size are marketable. Big timber is normally beyond the scope of the homestead farm.