Sensation said:
What are the best (and fastest) ways to get to know how the rails react?
Drills, Special techniques...
Do you mean the rails of a specific table, or the principles in general?
For the general principles, start
here.
To quickly get familiar with a given table's rails, try this set of shots:
With cue ball in left head corner and aiming at the dead center of the CB, shoot to each diamond on the foot rail and observe the rebound. Then move the CB to the right corner pocket and repeat. Move to the foot of the table and repeat.
From a side pocket, shoot the CB to each diamond on the opposite rail using center-ball hit, and observe the rebound. Then repeat from the other side pocket.
Look for "funny" rebounds: off-key sounds that indicate loose cushions; odd hops that indicate a low spot in a cushion.
This routine won't catch every anomaly in the rails; you'd need an infinite number of shots to test every point on each rail. But it should help you find significant stretches of bad rail.