My league doesn't have a draft party since the draft is online...however, I'll share the playoff setup we have.
Our 16-team league has 4 divisions of 4 teams. AL West, AL East, NL West, NL East.
The top 2 teams of each division gets in the championship bracket.
The other teams are in the consolation bracket. 1st and 2nd place of the consolation bracket get the 1st 2 picks of the draft the following year. This setup keeps things competitive to the last week of the season. Furthermore, each playoff matchup is 2 weeks long, not the traditional 1 week. (Our playoffs are 6 weeks long)
In your league, I'd consider using 2 divisions of 6 teams. Winner of each division gets a bye week.
Will always help in return (leave a link to your question in response)