Order of play
The same board can be finished with one order and abandoned with another.
Top first
A tile in a higher layer covers more of the board than any other move you could make. Even when the pair you want sits at the bottom, take the top one out of the way first.
Edge before centre
Edge tiles are open on one side by definition. Following the perimeter keeps the middle from closing up.
What to leave for later
Tiles that pin down several others should go early. Isolated tiles on the bottom layer can wait — they block nothing.