Minesweeper, to those who do not know the strategies involved, is a difficult game.

What patterns exist in the game which I can take advantage of?

Meta-context: this question is an offshoot of the current original question, for which the scope has been changed to be simply pattern-based. Feedback indicated this was somewhat too broad. This question has now been edited to address these concerns. Please contribute to discussion on Meta if you feel inclined.