What I tend to do with a new team is draw them all out on paper.
First I draw a grid that has all the positions where you can place players in a tactic IE: Fullback, Center Midfield etc...
Then I tick the related position for every player I have in the 1st AND reserve teams who plays that position naturally.
From that I get a rough idea of what shape/s I can use and where we have depth.
I also learn from this if we have too many or too few players in critical areas.
I will then use the filters to go through the players one by one, section by section, left/right/center and defence/midfield/attack.
I look at things like ability, potential, personality and for the key skills that I want players to have or that are particular to my style of football.
At this point I make notes of secondary positions and try to come up with a formula where by I have two players for every position, this might mean playing a player in a less favored position for a season or so.
After all this is done I usually have a goodish feel for the players and why types of football they could play and in what formations, I also have a pretty good idea who is not in my plans and who just has got to go.
I have looked at the backroom staff's formation recommendations and often I have come to a different conclusion based on the results of my draw it "draw it on paper method" because the staff obviously can't take into account what my interpretation of what I think suits the team best.
It's from this point I will try and get closer to my style of play.
I don't have a single 'killer' tactic that I try to impose on every team I play, just a general stand off pass and move ideology.
I also manage the U18 side too but I am more brutal in culling players who don't fit the mold.