Improve your agility and quickness with ladder drills. Practice ladder drills 1-2 times a week and concentrate on doing the exercises correctly. You can add more speed to the exercises as you progress.
In many ways, quickness and agility are more important than straight-ahead speed. A player rarely reaches maximum speed during game competition. Having great change-of-direction speed (agility with quickness) allows you to beat your opponent "to the spot" or recover from mistakes in positioning.
How many times have you seen a player with "not great speed" repeatedly make plays to help the team win. This is not an accident. You can improve your change-of-direction speed with proper training. Read my post that discusses change-of-direction speed in detail.
You can also improve quickness by improving your reaction time . You do this by training to make the right choices as quickly as possible. You can practice reacting to sight or sound cues.