DC Sudoku Strategy - Some Sudoku Solving Ideas

Example #1 - Beginner Level Puzzle: A very easy puzzle solved using two strategies that are applicable to a large part of the solving of most sudoku puzzles.
Example #2 - Easy Puzzle: A slightly more difficult example than the beginner puzzle. It is solved mostly with the same strategies. One new strategy is introduced and the final steps use multiple strategies per step to save time.
Example #3: A slightly more difficult example than the easy puzzle. It is solved mostly with the same strategies but combines steps together to demonstrate efficient solving and doesn't bother with descriptions, only strategy diagrams.
Example #4 - more challenging methods: The solution to this puzzle introduces some multistep strategies.
Example #5 - similar level to example #4: The solution to this puzzle uses some multistep strategies.
"Using the Rules of the Game": An interesting strategy my brother showed me.