Diversify financially. An ecologically sustainable farming operation won't do anybody much good if it can't generate a profit and keep itself running. Unless you or someone else is willing and able to sponsor the farm with an off-farm day job or another external source of income, you're going to have to crunch the numbers until you're in the black.
Take advantage of the options available to you as far as direct marketing is concerned. That includes: CSA/subscriptions, farmers markets, roadside stands, and even the Internet.
Adding value to products is a smart way to differentiate this farm's lettuce from that farm's lettuce. When you take your lettuce and make it part of delicious burger made from healthy meat that was pasture-raised in your own fields and top it with a slice of tasty, red tomato that grew in your own soil, you stand to appeal to a wider audience and rake in more profits. In other words, don't just grow a wider variety of stuff––do a wider variety of things with the stuff you grow, and consider selling it from an on-farm store or restaurant (as well as on the Internet).
Cater to every economic level and ethnic group in the community. People of varying wealth seek different things from a farm. Certain ethnic groups value farm products that the mainstream community has no interest in (for example, many Caribbean immigrants seek male.
Publicize. Talk to everyone about what you're doing at the farm. Provide educational tours and workshops. Keep your farm looking nice, because if it ever comes down to it, the local community may fight development proposals because they perceive your farm to be a haven of agricultural heritage.