Layout
Trying to have at least one location empty at all times to place the large 3x3 piece. If possible, even try to have to locations for that size of piece as you can get it twice in a row. In later levels, the same thing should be done for the 5x1 piece that will begin to appear. Create rows vertically or horizontally. You do not have to go for horizontal lines only. Also consider creating vertical lines when needed. You can also consider filling the level with pieces and waiting for the perfect one to remove a few rows instead of working on one row at a time. However, this strategy will not allow you to save open space for larger pieces.
