These methodologies can come in the form of sweeping all-inclusive theories (such as Marxism or liberalism), historically useful conceptualizations (borderlands, the "frontier," national identity or nationalism)
or particular areas of study (diplomatic history, social history, gender history, political history).
The methodology used by the historian can influence the questions asked, the types of evidence consulted (oral histories, government documents, cultural artifacts, public speech), the accepted evidentiary standard, and the nature of causation.
In history, it helps to keep in mind that there are many different ways of determining how history happens. (cf. major approaches/schools in psychology-structuralism, functionalism, psychoanalysis, humanism.)
Historians disagree very much over why almost any event happened.
The following list of selected historians can give you some ideas of how the great historians "did" history
MAJOR APPROACHES Major Approaches Great Men Marxist Toynbee Radical History Boorstin Geographical determinism
What matters, is that the great Creators and Discoverers have been open to the challenge and took previously unrelated ideas and put them together in a way that was entirely new. They thus change the world.
An example is how an anonymous optician in Belgium created the first telescope to be used in combat