Do you practice with your double rifle? YES, very much so

Do you have a routine you go through? YES, very much so
such as making sure your clothing and ammo holder are in the same place as when you will be hunting. You will son find out on the range any possible hiccups.

What other types of pressure do you put on yourself to
preform? Shoot and reloading, starting off slowly to get the sequence going, then practice it faster but while still maintaining accuracy (ie so still shoot at multiple targets).