Sounds simple, but dribble with your left. Start low to the ground and pound the ball hard with your left hand. You can alternate between high dribbles and low dribbles. Also, to get better moving up and down the floor with your left hand find a place where you can run and drill hard with your left hand as fast as you can up and down the floor. The key to improving your handles is of course going hard and pushing yourself, but dribbling as hard as you can is what gets you comfortable with the ball. There are alot of drill you can even make up for yourself just make sure you dribble hard.

well what i do is every morning i get a basketball and do drills like i will zig zag across the driveway and every time i turn i will go between the legs or behind the back or cross over.

Bro first you got to know fundementals,after that look up some drills you can do to improve.It worked for me.I'm a 13 year old 5'10'' small forward and I dribble like a Point guard.

what i did to become a good dribbler is i would take my basketball with me every where i walked and dribble switching hands from time to time as i grew more confident i would add dribble moves and now im one of the best dribblers on my team and ima post