The "Accidental Entrepreneur" Plan: Believe it or not, it happens quite often. An impulse, a hobby, or a passing notion turns into a business without warning. One day you're handing your extra back_yard tomatoes or homemade cake to the neighbors, and before you know it you're filling out the forms for a booth at the local farmer's market. Perhaps you create a unique bit of hand_crafted jewelry and wear it to school or work, and then find your phone flooded with messages like, "Where can I get one?" and "I'll pay you to make one for me."
If you need to get going quickly to ride the wave of a fad before it fizzles, then fast, bare_bones planning may be all you've got time to execute. This works best when you've already got the infrastructure in place, perhaps from previous projects or an established business, and you can simply shift energy and resources to the new idea.