Slow down the decision
Before each move, ask what information is certain, what is only possible and what consequence the move creates.
Use a repeatable strategy
Use elimination across the row, column and box together.
Re-scan the board after every confirmed number because new singles may appear.
- Begin with rows, columns or boxes that already contain many numbers.
- Look for a number that has only one possible position in a unit.
Recover from mistakes
A weak move does not always end the round. Reassess the board, protect the most important area and avoid compounding one mistake with another rushed decision.
What to avoid
Use these mistakes as a quick checklist before important moves.
- Guessing when a logical deduction is still available.
- Checking only the row and forgetting the box or column.