Here is short article I wrote on drills for dribbling that I find most effective.

Note: Keeping your head up is a must for all drills.

One-ball Drills:

Kills: Dribble the ball high up, then dribble low. Repeat as many times as needed.
Note: when dribbling low, don't just simply bend your back down to reach the ball, bend your knees.

Crossover around leg: Dribble the ball under a leg left and right without switching legs. Switch legs.
Note: When you get better, you can simply walk and crossover the ball between your legs, or on a spot and shuffle the legs back and forth.

Swing Crossover: Large swings in your crossovers left and right.

Normal Crossover: Dribble once on the right/left side and crossover. Repeat.
This can also be done behind the back.

V-dribble: Dribble using one hand left and right in front of you like a crossover, or front and back from the side of your body.

Figure 8: Keep the ball low and dribble like a 8 around both legs using both hands, I would recommend doing them around one leg at first, then progressing onto the Figure 8.

Wall Dribbles: This is a relatively un-used method, but start dribbling at below head level. Then dribble 2/3 inches from the wall and go up and down. Do this for around 1 minute each hand and repeat if neccesary.

End-to-End Dribble: Dribble as fast as you can from baseline to baseline. Do a jump-stop and then do the normal crossover drill. Switch and go back.

The Spider: Almost everyone knows this one. Left and right from the back, left and right from the front, while keeping the ball in between your legs at one spot. This drill is an exception to the keep your head up.

Zig Zags: Go the right side of the court to the left, and when switching hands, either crossover or bounce the ball between your legs. Sometimes crossover real fast, or slow. This drill can also be done with chairs set up in a line or in a zig-zag and to crossover/bounce the balls between your legs once you meet the chair.

Two-ball Drills:

High and Low: Dribble the two balls simultaneously high 2 times, then low 2 times. Repeat. This can also be done one after another, instead of simultaneously.

V-dribble: Just like the one-ball V-dribble, but using two.

Two-ball sprints: Both balls are bounced simultaneously while speed dribbling down the floor. Also can be down one after another.

Dribble around leg: Dribble both balls low while one arm dribbles a ball around the leg. The other ball does not do anything except dribble in place.

Two Balls from Behind: Dribble the balls twice simultaneously then wrap them around your leg from behind, and continue dribbling. Do this while moving forward.

Josh.