How should one best go about selecting a career that suites their personality,
Unfortunately or fortunately, there is no pat answer to your question from a philosophical point of view. There are, however, a few general points that might be of use:
Socrates admonished the people of Athens for spending their lives in the ambitious pursuit of wealth and power rather than seeking to cultivate the soul. There is a rich 'care of the soul' tradition from Socrates on up through the medievals in which we are called to use time wisely and reflectively. For an overview of this tradition, check out Richard Sorabji's Emotion and Peace of Mind: From Stoic Agitation to Christian Temptation (Oxford). Socrates is well known for highlighting the importance of reflection ("The unexamined life is not worth living") and so he would probably respond to your question by asking you to engage in careful examination of all options and the reasons behind each.
Values: Philosophers like Pascal and William James thought that our beliefs and practices should be shaped by the values that are in play. They would recommend that you consider matters of a career choice in light of values. For example, if you were deciding between law and medicine and you are living in a country where there are an abundance of doctors but almost no lawyers and there is a perceived need for your country to have more lawyers, that may count as an important factor for you to choose a career in law.
Integrity: Philophers like Kant would recommend you not to take up any career that is incompatible with treating other people with respect.
Beauty: Philosophers in the Platonic tradition, from Plato himself and Diotima on through the Renaissance and the Cambridge Platonists would probably recommend that you choose a career that would be both itself beautiful and contribute to the love of the beautiful (as well as the good and the true).
Reverence: Philosophical theologians also in the Platonic tradition but also reformed theologians like Luther and Calvin, along with Hindu philosophers, would recommend choosing a career that you can recognize as in some way sacred (worthy of reverence).
Luck: Philosophers like Boethius in the fifth century would also remind you that so much of worldly careers involve luck or fortune and this can make you quite vulnerable in life. Boethius would therefore probably recommend that you pursue an honorable career, but also keep in mind that there might be higher values (he wrote an important work on eternity) that call for attention and will be important in times of misfortune or that time when all our careers on earth will come to an end.