Part of teaching your players how to move and position themselves is their understanding of which gaps exist when the ball is in a specific location. Those gaps must be filled quickly by moving teammates at the critical point in time for a zone to be successfully attacked. A quick duck in from the weakside wing, or step up by a post from the baseline when the ball is at a specific position can be deadly against zones, especially if those duck-in's occur from behind the zone. Show them the possibilities if the ball can be entered to a player or from the dribble into these gaps. I believe this is the most critical element most often undertaught against zones.
Most players receiving the ball on the interior of a zone receive it in tight quarters.
They have little time to react and execute before two or more defenders swarm the ball. A player should know without a doubt that a second post player is, for example, ducking under the zone baseline, or a weakside wing flaring. This takes a considerable amount of practice and certainly doesn't involve just moving the ball around, or running a pattern. Another important factor when attacking zones is that ball movement is slower than the shifting movement of the defensive zone. You must practice more rapid ball movement in combination with slashes into passing or scoring gaps.