Brainstorming ideas that take into account what you love to do and the lifestyle you want to have is the most important..most skills you can learn or find a partner with skills you need but don't have. Consider the demographics of your area and current trends (green, healthy food, what might not be available, etc) as you create an idea.
Ideas that popped into my head: grow flowers and sell a "weekly bouquet" that gets delivered to their door..sell memberships at local farmers market,etc. Especially the antique flower varieties with info about them, seedlings, delivered in a container from the era.. or herbal teas..tea parties.