Close CallG 20

It's recommended that you expose your 2 target lightning tiles as quickly as possible. Once they are exposed and can be matched at any time, you are free to play with the entire rest of the puzzle, and you can safely tick turns away, 1-by-1 until your target tiles reach 1, and since you exposed them early on, you are free to simply match them at your leisure.

While not required for the achievement, in the interest of progressing toward your medals, try to spend your time ticking the turns away pursuing the rest of the lightning tiles and clearing them. By doing this, you will be in good shape to simply finish the puzzle once you've unlocked your achievement and grab the coins for that month's medals.