There is a trick that the diamond systems don't tell you--well they do, but its deap in the fine print. That is, the diamond systems are dependent on the way you hit the cue-ball. Most diamond systems require you to use running english. The reflective diamond system requires you to not use running english.
Secondly, the angle of reflection is dependent on the speed at which the cue-ball impacts the rail. The faster the speed, the less the angle of reflection. Another point, here, is that the cue-ball picks up side-spin as it encounters the rail, changing its reflecting angle on subsequent rails and changing the angle of contact if it hits an object-ball.
And then finally, notice that the missing diamond (the one a the corner pocket) is not in the center of the pocket! Measure it: take two diamonds as a reference and then measure from the first diamond to the pocket. Put a mark there to remind yourself where it really is.
With all these nuances to accomodate, what works best is to simply put 1 hour of banks and kicks into your daily practice session. Kick from corner to side, corner to corner, side to corner. Notice, carefully, that the corner to side has the cue-ball follow the same line as the side to corner but it looks a full inch different because of how the diamonds are recessed from the point of reflection.
Once you start getting the banks and kicks, start adding vertical englich (follow and draw) and see how these alter the shape of the reflecting ball "just after" reflecting off the rail. These become VERY useful later on when a simply kick is blocked. Once you see the subtle change in direction and get a grip on it, then start working on side-spin and see how this alters the angle of reflection immediately at the point of reflection. By seeing and understanding these two phenomona you can craft many shots to save your a$$. Then finally, for banks only, hit the object-ball softly with lots of side-spin on the cue-ball and watch how the object ball takes an angle off the rail. You can use these kinds of shots to manouver the object-ball around interfering balls and still pot them on command.
Diamond systems only get you started by pointing you in a geometric direction. Practice the above independently and you won't need the diamond systems and can simply see the reflection and the "physics of reflection" due to side-spin and verticla-spins.