While a lot of the information mentioned above is important, imo, the best situation you can put yourself in is a head on merge where you are nosed up 45 degrees or greater up at him, and he is nosed down 45 degrees or steeper at you. When you get yourself into this advantageous position, you are able to loop over on him and get gun solution very easily on the next pass. I'm not going to bore you with the physics behind why this is so advantageous(agent touched on it), but most good pilots know this anyways.
How to set this up? Obviously the best way to accomplish this is to nose down at icon range and try to get 2-3k below your enemy and then nosing up at him on the merge. This will work a lot of the time against the new pilots but can easily be countered by your enemy nosing down to match your dive. If your enemy does nose down with you, it's not over yet, there's still one more option you have to create the "Advantageous merge". After you guys merge, just blow right by him, most likely he will loop over. Give it a few seconds and bank into a low yo yo back at him at around 2-3k separation. He will now be nose down at you and you nose up at him, giving you a perfect opportunity for gun solution on the loop over. This is how I kill most spit16s in the ta152. If this fails you can dive out and rinse repeat or just try to fight the 'double superior' plane at face value.