With 4 machines and some simple fun, we did the following for our son's first tournament. Kids were younger, so may be too easy for teenagers.
1 machine for highest score
1 machine for closest score to XXXXX (revealed at the end of the tournament)
1 machine partners game for highest score
1 machine with most of the same number in the score (1,140,100)
Makes non-pinball players feel like they have a chance, prizes given for each category. Was a lot of fun, kids were lined up to play. Each game had two columns next to the players name for score recording (2 chances).