And do this with an open bridge. It will magnify your problems.
Well considering you don't want the drop during or right before contact I know of an easy drill that you don't need anyone's help with!
First think about what happens to the tip of the cue when you drop the elbow? It means the tip of the cue will come up right?
When hitting the cueball the ideal location of the cue would be level as most people will agree for most normal shots.
That being said with proper follow through after hitting the cue ball if you freeze then the proper placement of the tip should be slightly downward toward the table right?
Now with all that being said line up 7-8 balls along the header of the table (2 diamond spot) Now hit all those balls individually into the corner pockets at maximum speed and maximum top english on the balls.
If you are dipping your elbow this drill will provide very difficult, but trust me it will help you to quit dipping the elbow before the cue hits the ball.
Also get with Scott Lee or Randy G and they could give you some other drills to help ya out.