As a reminder - don't forget to also use your all surroundings to your advantage as well. I've written how one player would play safe and leave the cueball at the end of the table where her tall opponent had to awkwardly shoot b/c the table was too close to the next table. Or, how about when Shane rolled out to a spot that Alex (who is short) could not reach?
Know your opponents!
This is actually a huge part of the book I have always recommended, Winning Ugly, by Brad Gilbert. He would study his opponents and defeat the top players when most thought he was the underdog. I'd like to reiterate that this booked helped me gain the killer instinct and I highly recommend it for mental toughness (pretty amazing book that teaches a lot about competition).