pre shot routine is a very personal thing, some need to gee themselves up, some need to calm down, some need a 15 point checklist, some just get in there and do it.
Best example of this I can think of is yesterdays final round on the US golf tour, Tommy 2 gloves Gaineys caddy gives him the club then he just walks up and bashes it but on the other hand Jim Furyk has a full on board meeting with his caddy. Both fantastic players and contending for the win and totally different approaches to achieve the same result.
The more you shoot the more you will find out what works (or not) for you and your pre shot routine will evolve. Dont try to copy someone else, we are all wired differently.
Keep notes of how you shoot (copies of your scorecards etc), what you did beforehand, how you felt about shooting and over time a pattern will emerge. Take your notes to a decent coach and they should be able to tailor something for you.
I did this with Ed, we noticed I was hitting the first pair out on 75% of the stands I shot then dropping a few here and there. I used to load from the left pocket and line up the writing on the shells while waiting for the ref to sort the cards out before the first pair but then just chuck the shells in from the right pocket for the rest. He picked this up straight away and got me loading from the left and lining the shells up at all times to keep the same tempo throughout the stand. Even found myself doing it on live stuff now :.:
When you have a routine, stick to it at all times. Competition, practice, when you are shooting strawbales with mates, when its going good and even if the wheels are falling off a bit. In any sport you need a solid foundation and your pre shot routine is it.