I go a bit mental with this: fully vertical backrest, seat all the way up front, armrest goes ever so slightly tilting down (that usually gives a G5, but as always it is dependent on the particular aircraft) and then adjust the pedals so as to not be cramped as f***, but comfortable enough, being able to reach full travel without effort, but without feeling I've been bent in half while sitting there.
During the cruise I usually tilt the backrest back a bit and might move the seat a bit aft too, but not too much. I like to be in a position I know I can still fly the aircraft manually should it be necessary
I must however, emphasize using correctly the eye height level (i.e. the balls on the center windshield post). And I don't move the seat vertically once I set it because it's pretty hard for me to find the sweet spot again hahaha