The only things you'll really need to rely on in a dogfight are:
This is because you really just need to know where your opponent is in relation to you. All your CMD does is tell you the distance between you and the enemy. Eventually, you'll know when to fire and when to not. This is developed with situational awareness.
In a 1v1 head-on, there's really no need to use your CMD to identify a target, or indicate when to shoot, because you can VID your target and see him coming down the snot locker. If you can see the enemy in front of your 3/9 line, he's in front of you. If you don't see him in front of your 3/9 line, chances are he's making a move towards your six and/or is already there and firing. The CMD is only useful for telling you the exact distance you are from your opponent. Targeting is really a tactic used in 2v2's to spook out one of the bandits while going for another. Also, considering the fact that missiles are almost never used, dog-fighting here takes on a WWII-feel -just you and your opponent, with guns. Best man wins- you should not have to rely on much more than your sensor dishes, energy levels, and where you're pointing the craft.
Main Point: You can use your CMD and HUD, but remember that you don't have to wait for a green reticle and tone to fire.
Though it may not seem very important, there is something you must know. You can be too close to use your weapons. Have you ever been in an SP mission where you were close to your enemy when you vaped him, and as he exploded your craft was damaged? If so, you know what I'm talking about. If you have a feeling that when you vape your opponent, that his explosion will damage you or you won't be able to immediately pull up and away from his wreckage, chances are that you've exceeded your weapons envelope.