I've read that having multiple streams of income is a good idea- so that if one dries up, you aren't left up the creek. I would think a combination of basic product (meat, eggs, produce etc) and value-added product (leather, wool, chicks, pickles and other canned goods) and maybe some other things like hand-spun yarn, or wooden furniture, or clothing, or soap and candles.
Barter is NOT dead; it's just laying low. My DH's family had an arrangement with a neighbor that was a beautician-- she came by once a month and cut everyone's hair (there were seven of them in all) and in exchange they raised a pig for her each year. The only money involved was that she paid for the cut and wrap of the meat since an outside butcher was used. I had a casual friend that let me stay in her time-share in the mountains (lakeshore property!) for a week and in exchange I did a spring-cleaning on the cabin (It only took 3 of the 7 days, so the other 4 were vacation)