How to win rock paper scissors every time

1. Always throw paper first if you are playing a novice (novices will tend to play the 'strong' rock first subconsciously)
2. Always throw scissors first if you are playing someone more experienced (someone you think will know about people throwing rock first)
3. People subconsciously will throw whatever beat them last time. You can use this to your advantage
4. Watch the fingers, tension indicates what people are likely to throw down
5. People will very rarely throw three in a row the same, they think it looks predictable
6. Scissors are thrown more than any other form

From flowingdata.com