2 ideas. 1st, when you're doing nothing (e.g. watching TV) sit with your gun in your hand, hold it properly and slowly practise walking the trigger. focus on making sure your 1st finger pulls AND releases the trigger and then repeating with the second finger. very slowly build up the speed. just keep doing it until you can walk the trigger on your off hand as well as your strong hand.
2nd to make sure you have the correct posture you can stand facing a mirror, and use the edge of the mirror as your imaginary bunker. practise a slow snap shot movement until you can see your self in the mirror, and then move back to the start. repeat on both hands and assuming you already have decent form on your strong side, you can match it up to your off side so that both look the same.
the basic idea is to match up your poor hand to feel the same as your strong hand.