Here are a few Sudoku tips to improve your Sudoku skills:
Don't even think about trying a medium difficulty or advanced level puzzle until you're comfortable solving the easy puzzles first.
Go by box, then row, then column.
Look for easy rows, columns or 3x3 sections that contain 8, 7, 6 or 5 numbers.
Work through the remaining empty cells, trying the numbers that have not been used.
You will find numbers that can only be placed in one position considering the other numbers that are already in its row, column, and 3x3 grid.
There's no need to guess. If you haven't eliminated a box to a single possible number, keep looking.
Buy a book to practise your Sudoku skills. Some even have step-by-step instructions to improve more.
In the process of completing the puzzle, you'll need to jump from block to block.
If you make a mistake and ends with two of the same numbers in a row, column, or block, look around before you give up and start over.
If you get stuck on a puzzle, take a break and come back to it later.
Sudoku is a game of momentum. Every time you place a new number, the grid changes and new possibilities are revealed.
Copy the puzzle onto a grid much bigger, using a marker. Now, it's easier to add pencil marks.
Instead of writing pencil mark numbers, imagine each square as a 3x3 grid of dots. A dot in the upper right corner is a 3, one in the middle is a 5. A dot in the lower left corner is a 7.
For every cell you fill in, double check it.