Pre-Dive .. Develop a consistent picture of where the target is relative to an arc from your 12 to your 3 or 9 (depending which way you’re going to tip in on the target)
For instance: If you set up your offset such that the target hits your leading edge right at your .50 cal machine guns but your dive ends up being too shallow or too steep, then you know you want the target to hit your leading edge closer to the wing root or outboard your .50 cals
Developing a consistent sight picture will lead to more consistent attacks.
I fly the A-10C almost exclusively and I can easily perform a 30- or 20- degree dive bomb attack because I know from experience where I want my target relative to its height above my canopy rail and where it comes into view against my canopy bow. If I put my target in those same points every time, then I know my attacks will be the same every time.
Practice, practice, practice!