League Bylaw suggestions?

Had a fair bit of issues in a 12 person half ppr redraft league. (Had a team drop everyone and play only jets, Trade controversies, etc)
I am now commish and am replacing teams that were troublesome that’s not the issue.

As new leadership I wanted to make some rules more stated for everyone.
Anyone have anything on Vetos on trades, Fabb budget spending, any of the usually unwritten rule type things that have come up in leagues as controversy for any of you

Just want a fun league where it runs smooth and fair thanks for any help