How and with what authority does someone with Sola Scriptura determine which tradition is correct?

The question is above. The term Sola Scriptura: Belief that Scripture is the final and only infallible authority for the Christian in all matters of faith and practice. While there are other authorities, they are always fallible and the must always be tested by and submit to the Scriptures. The Adherents are generally speaking Reformed Protestants/Evangelicals --- Please note, This is not directed at those who believe in **solo** scriptura: The Belief that Scripture is the sole basis and authority in the life of the Christian. Tradition is useless and misleading, and creeds and confessions are the result of man-made traditions.