What do you enjoy? What can hold your interest? Several careers and professions need critical thinkers. The list is endless: business, accounting, management, law, medicine, physics, engineering, chemistry, teaching, and countless others. It is important to do something that you enjoy.
Basically, the important thing is to use them. Even if it is just a matter of trying to make sense of some complex political issue or a particularly challenging book, you should use your critical thinking skills, because (and I have absolutely no scientific evidence of this) it seems to me that if you don't, they weaken.
Use your critical thinking skills to find some problem around you. Once you determine the problem, use your critical thinking skills to devise a marketable, profitable solution to the problem. Use your critical thinking skills to build an empire, then donate millions to charity to change the world. Start with education.
The only thing that you can really do is to deploy these skills in some way that makes sense to you. You will benefit society (and yourself) the most if you put your skills to work doing something that is meaningful to you. That will allow you to do the best possible job and thereby help yourself and society to the greatest degree.
You could volunteer at a charity and try to help the charity assess its fundraising strategies.
Or you could become a writer and tackle popular subjects, applying your critical chops to issues like law, justice, politics, movies, music, science, or relationships.
You could begin by examining career choices for yourself, using your skills to accumulate and evaluate the available information. You might want to make a list of your strengths, interests, inclinations, habits, past experiences, etc, and sort them out, taxonomizing and measuring the strength of each entry: creative? People-oriented? Luxuries a necessity? Forward or backward ego balance? Patient or impatient? In other words, use your considerable reasoning skills and self-assessment confidence to set some long-range goals for yourself, based not on temporary and emotional criteria, but on the very logic you pride yourself on. What are your criteria? Money? Popularity? Fame? Security? World change? etc. And use your intelligence to distinguish between work and life-work. In the abstract, you should seek happiness with your skills. Use them to find your path to happiness. The is a mild, only mild, distinction between physical labor and mental labor (mind-work)—bit id you are truly confident in your mental powers, maybe you should concentrate on those careers requiring a good mind to start with—a “professional” career as they are called: architecture, law, medicine, engineering, education? Art, literature, dance? First step: know thyself.