Begin a soul-searching process to determine which business is right for you. You'll definitely have an advantage with a business that's a spin-off of your background or experience. You can also enjoy success in an area where you have strong interest yet lack experience, though you may need to qualify yourself through entrepreneurial training or professional certification programs.
Jot down the skills that already exist in your talent bank. What do you like to do with your time? What technical skills have you learned or developed? Do you have hobbies or interests that are marketable?
It might help to create a personal resume that lists your professional and personal experiences as well as your expertise. For each job you list, describe the duties you were responsible for and how successful you were at each. Be sure to include professional skills, educational background, hobbies and accomplishments that required expertise or special knowledge.
Don't forget the personality factor. Are you outgoing and friendly or do you prefer to keep to yourself? Do you like working indoors or outdoors? Do you enjoy working with the general public or with a few close clients? Do you love working 24/7 on an exciting project, or do you enjoy your downtime as much as your work time? Every business has its own personality, and your own personality should be a complement to the one you finally choose.
You should also talk with others in businesses similar to the ones you're considering about the traits and temperaments needed to be successful. Find out what they really like about the businesses they're running and also what they don't like. Compare their responses with your own interests and personality to see if there's a fit. Don't stop searching until you find an idea that couples your love for the work with your marketable talents.