Here is a quick way to find the bank angle. This works for any kind of aiming system. When using CTE for banking, the angle is crucial to pick the correct reference line and pivot. Here is a quick way to estimate the angle into the rail on a bank shot.
Simply visualize the mirror pocket, and aim as if you are shooting the ball directly into this pocket. This will give you the correct line for the bank. Then look down the dead ball hit line (the blue one) and estimate the angle between those two lines. This should give you a reasonable estimate for picking the right shot for the angle.
Now for the important tip: how to accurately find that mirror pocket. First, start off on a “known” aiming reference for the given bank shot that lies near the OB. In the illustration below, I use the line from the center pocket through the point opposite the 2nd diamond. This line passes through the mirror pocket. Find an object that sits at that spot, such as the corner of an adjacent table. The distance is important. Now stand behind the OB and site through to that same target. That will be the natural bank for the OB.
As you can see in the above example, the “known” line actually passes through opposite the 2nd diamond, not through it. This is the geometric center. You could also site through the 2nd diamond using natural running english, which is how I prefer to do it. Be sure to apply the same (outside) english to the bank shot.