If you are looking for a comprehensive system that allows you to solve almost any sudoku puzzle easy to the most challenging you should check out the book Top Secret Sudoku System.
This system allows you to solve almost any sudoku puzzle with a bare minimum of penciling in, rarely more than 2 numbers in any cell. It preserves ALL of the logic that makes Sudoku so addicting but gets rid of the need to sort through large numbers of penciled in possibilities.
It is so simple you will kick yourself for not having thought of it yourself, yet so powerful, you will need no other 'tricks' or specific situation strategies.
Check it out, it is on sale now at Amazon.com, type Top Secret Sudoku System into the search bar and elevate your game.