An Efficient Solving Order

Which techniques to try, and in what order.

It's most efficient to solve from easy techniques toward harder ones. Start by filling in every cell you can confirm with Full House and Naked/Hidden Singles.

Once there are no more Singles, use Pointing and Claiming to narrow down candidates, then look for Naked and Hidden Pairs. As candidates shrink, new Singles usually reappear.

If you're still stuck, try advanced techniques like X-Wing or XY-Wing. Getting into the habit of returning to the first step and rescanning after every move helps you avoid mistakes.