Pro tips:
-don't lose your tempo! always count how far each player is from the goal, and try to stay ahead.
-the amount of walls left is also a winning factor. don't waste them too early.
-common opening strategy is moving towards the center and placing walls behind you. cut down your opponent's paths while keeping yours open.
-the Twist hex can turn the game around if used correctly.
-analyze your games to learn from your mistakes.