There are 2 things every basketball player can work on no matter how talented they are.
1) Freethrows. There is no reason to miss a free throw. The basket is in the same place every time. The free throw line is in the same place every time. And there is nobody defending you. Make the basket! In other words practice... practice... practice...
2) Stamina. Running up and down the court is very tiring. You can build and condition your body to increase your stamina. Have a long distance running routine and a weigh room routine that you alternate between days.
I recommend any kind of conditioning. If you can out last the competition you can out play the competition. Also just carry a ball around with you everywhere and dribble it for fun. Overtime it will become 2nd nature and you wont even noticed your dribbling in a game, its almost like free movement.