I start from around 10,000 feet, at 2.5 -3 miles from target go inverted keeping a good lineup to target. 
At 2 miles, pull down, power down, and airbrakes out. 
Let the aimpoint go past the target, roll upright keeping the target in sight. 
As you get down to 4000 ft, pull the pipper through the target and release your bombs! 
Airbrakes in as you egress. 
 It takes some practice (took me 5-6 trys to get the method, and I still mess it up if I get distracted).  
It also helps to visualize the maneuver, try with a model or something, so you get an idea of how it works. 
With the A4, usually the bombs will hit between the outer and inner ring at 6 o'clock, slightly under the  bullseye. 
  
Good luck.