Tactical Rifleman got an Special Forces Instruction video on how to hold a pistol... "Gripping or holding the pistol is one of the more important fundamentals of shooing especially if you have multiple targets. With having a good grip on the firearm you want to hold it tight enough like holding a good firm handshake with someone.  You do not want to hold it like your trying to squeeze blood out of a rock.  Holding it this tight will fatigue your hand faster and make you have a slight shake.  When holding the gun properly with a firm grip it will help you manage the recoil better and also get the gun back on target for follow on shots if necessaryfaster."

Read further here and below is the video: