Tips for playing WORDS WITH FRIENDS:
1. Know your 2-letter words. By heart.
2. Don't plan ahead trying to figure out a word to play with your tiles. It is more important to see what your opponent has played and make your word decision based on that.
3. If you can't play a triple word tile, do everything you can to block your opponent from also being able to play a triple word tile.
4. Keep track of the blank and S tiles. Knowing where they are and how many there are helps you to know what possibilities you and your opponent have to pluralize words and also move in another direction.
5. If you get stuck towards the very end with a JXQ or Z, swap it at the last and force it into your opponent's hand. Chances are they will get stuck with it and have it count against them.
6. Longer words are not always better unless you are maximizing high value tiles. You may just be wasting tiles for a few extra points instead of maximizing a short space.
7. Think ahead to how your playing a word may open up the possibility for your opponent to play on a triple word tile and score big points. Always be thinking how they can play and what they could play.