Try to end each turn adding fewer exits (open ends) than you close.
If you need to play a tile that adds exits, try to arrange the new tile in so that following tile(s) played will close more exits than it adds.
The ‘u-shaped’ tile is best to use, try align two exits next to each other in order to exploit this tile.
Be careful of the constraints that begin to develop as you add tiles to a confined area. You’ll lose the game if you can’t close an exit in a confined area. These constraints develop quickly once you begin to get boxed-in. Avoid adding tiles within a confined area if possible, beware of this trap.
Try to balance pointing new open ends away from congestion, with the desire to align open ends in adjacent or perpendicular grouping which can then be closed with the appropriate tile.