I've always believed in hitting the same spot with my jab and my straight right. The great Freddie Welsh reportedly made a spot on his heavy bag and he would land his jab there every time. I'm also a big believer in accuracy with one's punches. Use tape of a marker and mark targets on your bag for the liver, the solar plexus and so on, and hit those marks with the punches. On the pads...well, a lot of trainers don't really give accurate targets. I like to work real close, where you have to step in and throw the punch properly to land a good "body" punch, and so on. I don't think its of much benefit to catch the punches away from you.