Instructions
Ask whether you may dual wield pistols before firing. Some ranges do not allow this practice.
Choose the guns you wish to dual wield. Single action pistols would not be helpful when dual wielding, since they require cocking after each shot.
Figure out which of your hands is better able to control a gun or fire it more accurately when dual wielding pistols. This may not necessarily be your dominant hand.
Hold the pistol that recoils less in your dominant hand when dual wielding pistols. This will ensure that you will have a better chance of being accurate with this hand when dual wielding.
Use two of the same pistols, choosing ones that don't have much recoil if you wish to be more accurate with both hands.
Alternate firing your pistols as you dual wield. This will allow you to aim between each shot.
Shoot at the same target if you decide to fire both pistols at once. This will ensure you hit your target, rather than taking the risk of firing blind.
Be safe. Wear ear and eye protection, and be aware of what's around you whether you're dual wielding pistols or firing them singly. Gun safety is paramount.