For the OP, these are the kind of things you do not want to practice. How you grip a gun is of extreme importance to shooting accurately and fast. Choking the gun with a death grip is neither fast or accurate. The trigger hand needs to be somewhat relaxed with the grip hand somewhat firm. I used to go for about a 60-40 / 70-30%. Always made a measurable difference in my split times. Again I suggest getting help from an experienced competition shooter.
I don't shoot competitively besides bowling pin matches but I have several friends who are A class, Master and Grandmaster in USPSA and they all say grip the piss out of the pistol. Not trying to start a debate, but it has for sure helped me. If I remembered to grip my pistol hard, my bowling pin times were usually about 1 second faster(4 seconds for 5 pins)