Make a General, but clear in essence the idea of your desired career. By whom, in what status, with what style of life, with what degree of professionalism, fulfillment, and even ambitions you would like to see themselves as, for example, two five-year plan. If the answer is more or less certain you'll understand that some of the professions where your vision of the future is not right for you.
Analyze the facts existing experience (school practice, everyday Affairs), how certain types of activities relevant to you. Your temperament, mentality. If they do not come in conflict with the soul and body"? Well, if you had a real business, which was pleased with the result, brought satisfaction and made to feel like an adult and Mature person. If you clock fun to sit at the computer, successfully mastered a difficult program, won in the competition and constantly strive for self-education in computer technology - it is a signal reference.
For guidance important to an adequate assessment of your abilities in a particular area of activity. Someone "suddenly" begins to dream of becoming a designer, but, alas, draws more than mediocre, and erudition in the question - zero. It is not serious. But if behind - successful learning in art school, and artistic taste have been appreciated by awards, then the chance to succeed in business-the dream is real.
Another important factor is the demand of society for the profession, its relevance. Study the trends of the labour market in the region, where to live and work, analytical predictions. Perhaps there are several specializations that suits you, or you are faced with the choice of "fifty-fifty". Stop your choice on the activities that does not fall in the coming years in the category of "unnecessary."
A win-win when all the factors influencing the choice of profession for you happily coincided. Then the prospects for future vocation is clear, and can be targeted to achieve the goal. Harder if you have not formed clear ideas about desired activities and their potential. In such a situation it is better to consult with competent experts in the field of career guidance. Experienced consultants will help to objectively evaluate your capabilities and desire to provide useful information on the labour market, the relevance of professions. Many services in this area don't even resort to tests - only interview and a long conversation.