My league's broken into three divisions (12 teams). 3 division winners are guaranteed playoff spots, and one team with the best win/loss record that didn't win a division is given a wildcard spot.

If the record is tied for the division lead, whoever has the best division record wins, and if that is tied as well whoever has the most YTD points scored wins. For the wildcard, the lone tiebreaker is YTD points scored.

You could also use head-to-head records with whichever teams are tied.