@Graeme said: " always keep in mind the end goal. Work out how you want the story to end, and then write in that direction. Don't lose sight of that goal, because that's how you can write yourself into a corner. If you know where you're headed, that will help remind you to leave an escape route to allow you to get to that goal. Meandering on your way to the goal is fine, but don't forget where you want to finish while you wander."
In my experience this is a truth worth repeating!