I'm partial to the "4 quarters" format (5 TU/5
boni in one category), if only because I used that as
a theme in an Anarchy Bowl (Texas A&M trash
tournament) packet. Of course, certain themes may lend
themselves more to different setups (say 40 tossups on Texas
events or two mini-themes of 5 TU/boni each on certain
subjects with 10 tossup lightning rounds that would cover
the typical format canon). By all means, experiment
and pick something you think would fit in well with
what you want to do, or the format that would most
naturally fit your theme(s).
Brian