My routine starts with packing, I check and double check that I have everything from weighed pellets, air, shooting clothes, change of clothes, various waterproofs and warm clothes, etc, etc. The night before is pretty laid back with a meal and a few beers but i will make sure all my shooting clothes are laid out and anything uneeded is packed to the bottom of the bag ready for the off in the morning. Then on shoot day I will make sure I have spare pellets as well as those in my pouch and then it just goes into auto pilot with shot routine.....
Shot routine goes like this..approach target mentally estimating range while cocking gun, inspect pellet and load, slide cocking lever forward but not closed unless its a standing shot, get into position, check barrel is clear of rubbish, bracket target while looking for windage, when im ready to go i'll pull my hat down and push glasses on and close the bolt while taking a final breath before the shot, slowly release breath and then...GO!!!
Standing is much the same but i'll close the cocking lever straight away and take a few breathes to get comfortable. Takes ages to read but can be done easily in under a minute and at the UK Matchplay i was taking shots in all 3 positions as quick as 20seconds and still going through the full routine
OCD? probably but if it makes me a better shot I don't care