Place the brass you are sizing, decapping etc in the shell holder with the hand you operate the handle of the press with. This will keep you from learning the messy/bloody way what a decapping pin does to your index finger.
It is amazing that when you feel resistance on the press handle your instinct is to push harder no matter how much pain it is causing to your other hand.
I've got the scar on my left-hand index finger that proves I learned this lesson the hard way!
In a time of universal deceit, telling the truth is a revolutionary act.