Teaching players to set good screens
A screen or "pick" occurs when an offensive player attempts to block, or "screen", a defensive player away from the man he is guarding, thereby freeing up that offensive player for an open shot or pass.
Setting good screens (or "picks") is a very important fundamental part of the game. It is often assumed that players will know how to do this, but like any other important fundamental, it must be taught correctly.
Unfortunately here in Malta I witness a number of flaws when screens are set, often with the offensive screener moving illegally instead of waiting for his teammate to make good use of his screen.
Screens are most helpful in freeing up a teammate against a man-to-man defense, and in out-of-bound plays. Setting good picks are basic to most offensive plays. The "pick and roll" is still one of the simplest plays, but when done correctly, one of the most difficult to defend.

Those who are my age easily remember the Utah Jazz's duo, John Stockton and Karl Malone who were masters of the pick and roll.
Important elements in setting an effective screen.
1. The screener must make contact with (but NOT foul, hold or push) the defender that he/she is trying to block. If you do not make contact, and get up tight, the defender will simply slide around you. Obviously, it is the teammates’ task to bring the defender onto the screener.
2. Be strong. Get your feet wide and plant your feet solidly. Do not move your feet once you have established this position or you will get called for a "moving screen" (a foul). You must be stationary and not move with the defender, and you must not push the defender away. If a defender bumps into you and you are not stationary, you will probably be called for the foul.
3. Keep your arms tucked into your chest, not only to physically protect yourself, but also so the ref can see that you are not pushing with your hands, or grabbing or holding the defender.
4. The angle, or direction, of the pick and the timing of the pick are probably the most important, and most overlooked factors in setting a screen. This is the real secret and the fulcrum of good screens. You must have the correct angle, or position, when you set the pick. You must anticipate the direction that your offensive teammate wants to go, and then make contact with his defender in a position so that you are directly in the way of the defender, and he/she cannot get around you. If you don't get the right angle, the defender will simply slide around you. Perhaps this is best demonstrated in the diagram. In Diagram A, the screener does not make contact, and the defender slips behind. In Diagram B, the pick is too high ( a common mistake), and the defender slides behind the pick and stays with the defender. In Diagram C, the pick is too low, and the defender can fight over the screen. Diagram D shows a good pick, followed by screener "rolling" to the hoop.
5. After your teammate cuts around the screen, the screener "seals" off the screened defender and "rolls" (cuts) toward the hoop. If the defense switches the screen, often the "roller" will be open for the pass.

6. The offensive player receiving the screen must cut hard, and close to the teammate setting the screen. You must "rub off" your teammate's screen... that is, brush against him as you go by. If you don't brush close to the screen, the defender can slip through the screen.