Various Tips and Tricks
The key is to watch out for open spaces. As you slide number tiles in all given directions - up, down, left and right - they'll shift depending on the number of open spaces. If you see an opportunity to add bigger numbered cards - for instance, 64 into 64 - don't hesitate to do it. This frees up space on the board, with one less tile to worry about. When you can, be sure to add smaller numbered cards. Otherwise, you could run into a situation where a 2 or a 4 card easily becomes surrounded by higher ones - and you won't get a chance to add it to anything.
The higher numbered cards you end up with on the board, the better the score. The overall goal is to get to a 2048 card, but as you might guess, that's a massive task. Add as many cards as possible to get bigger numbered cards, like 256 and 1024. The higher the points, the better you'll fare overall through the game's online leaderboards.