A good way to use Pirate Ship is to attack enough to get it up to $4, then use a village to play two Pirate Ships and get a province, buying additional villages or Pirate Ships when you play only one. As with most Pirate Ship strategies, this requires a game with more than two players, or else you will have a lot of misses.
The Native Village works particularly well for this strategy, because you can control when you get two Pirate Ships and play both of them, using your mat to save a Pirate Ship for a double. If you have no Pirate Ship on your mat, use Native Village to put a card on your mat every time. If you have one Pirate Ship on your mat, take your mat when you have exactly one Pirate Ship in hand, and put a card on your mat when you have zero or two. If you have two Pirate Ships on your mat, take your mat unless you already have two in hand (in which case you can wait for the next village).
An additional benefit is that Native Village is cheap. You will have turns with only two copper in hand, and either no Pirate Ships or the ships needed for attacking; you can use these to buy more Native Villages.