View attachment 575760
Try shooting this shot. Both balls should be 1/2 inch off of the rail. This will give you a good visual to identify anything that is not in line. This is also a good shot to video so others on the forum can critique. Shoot this so the one ball is closest to the camera looking directly at the shooter.
If you have a Rempe cue ball, use it to determine if your chalk mark is contacting in the center of the cue ball. If you do not have the Rempe just use a measles ball or stripe to see any undesired rotation.