The cone touches basketball dribbling drill is a great drill because you are able to combine working on ball handling, conditioning, thinking, and competition all in the same basketball drill. The competition aspect will help push the players to compete harder than they most likely would by themselves.
To be a great ball handler you need to not only be able to dribble the basketball, but also be able think and read the defense as well. This drill will fatigue the ball handler, and then make them think while they are tired. It is really good end of game training, because players tend to lose mental focus as they get tired down the stretch of a game.