Personally, I just do whatever fits my current playstyle and what seems fun. With Expanded Traditions you end up having lots of choice.
Just spend some time reading through them and pick the one you want. You don't need to pick Ascension Perks right away and you can just keep them empty until you are sure about what you want.

Edit: I always like to pick up the Ascension Perk that gives you +50% influence

Going full research with a Fanatic Materialist and adopting the perk "Progression, else Regression" can result in unlocking traditions insanely fast which is useful if you use a tradition expansion mod like Plentiful Traditions. Other than that I always get “Ascendancy of the State” since that extra civic slot is pretty useful and the added influence is a nice bonus.