Thy kingdom come, Thy will be done. The first decision in any decision is to discern what God wants and to do it, and everything else will fall into place. The only sensible major for any of us, if the Bible is right, is to major on God, to connect with God at the center of our lives and then integrate everything else around that center. Wisdom begins with God. Wisdom is knowledge, but it is also discernment.
Wisdom is sound thought, but it is also right behavior.
In the Old Testament, the Hebrew priests had the Urim and Thummim, sacred stones they would use to discern God's will. They would pray, toss the Urim and Thummim in the air, and read God's will from the way they landed. That's like flipping a coin or letting your Bible fall open and sticking your finger on the page to see what God tells you. I tried that once. So I wouldn't recommend this method.