In a saga I played in, we chose the tribunal by everyone getting 3 votes for tribunals they'd like to play in, and one veto of a tribunal they didn't want to play in. People's vetoes ruled out several different places, and of the places people voted for Stonehenge came top and Hibernia second so we went with Stonehenge. Covenant season was chosen by the fact our alpha SG nearly always has spring or winter covenants.
I think asking people what they don't want is important, so are there any stories they don't want (like less mundane interaction, so maybe an isolated covenant).
For house rules, the quickest way is to ask people what spells or magical items they think their character wants to do most. You can then check if your understanding and their understanding of these match.
To use two popular examples:
Teleporting - if you use Leap of Homecoming, does a magus take their clothes and personal possessions with them or do they need requisites for this? If someone makes a ReCo specialist to do this and you insist on requisites, they need to know before character creation.
Creatures of magical might - some people don't like the might-stripping spells such as Demon's Eternal Oblivion and its magic and faerie counterparts, and are particularly concerned about people multi-casting low level versions of these. They make house rules about how this works - sorting this out is important if someone is playing a PeVi specialist.
There's been a few threads of people asking for house rules in the past (I think I once did one asking for house rules to check at the start of a saga) but the forum is not letting search work right now.
EDIT: Search is now working, my thread is here
A big thread was this one
The one referencing Project Redcap is this one