Use the numbers to find out where nearby mines are.
Place flags where you suspect there are mines. Note that even though the indicated number of mines goes down when you place a flag, there might not be a mine under the flag.
Think before you click, a wrong click could detonate a mine.
When you suspect that a square contains a mine, work around the square to uncover any numbers which might help.
Try to clear the board as quickly as possible, the less time you spend, the higher your score will be.