Wherever you decide to place your weapon(s) practice drawing them - under stress if possible. Personally I carry one gun in the same place all the time and practice deploying it. My thinking is that if I ever have to need it I want the draw to be instinctive. I will already be behind with respect to time and don't want to lose anymore by grabbing the wrong spot or hesitating to remember where I put the gun today. Those with superior skills may not have my concerns.