Practice

To improve your casting you need to practice. Find a spot that you can walk to that has enough room for you to cast: try a local school yard or park. Practice with a length of line outside the rod tip that you can cast correctly with tight loops. Add two or three feet of line and cast that length of line until you have created the muscle memory for that line length. If it all falls apart shorten the length of line that you are trying to cast.

Fly Line and Leader Coiled Up?

Help your casting by straightening your fly line and leader. Your line and leader have a memory, a set, from being wound up on a fly reel. The memory shows itself in the tight coils when you strip line off your reel to start casting. Straighten the line by stretching it, either in short lenghts with your hands, in longer lenths with the help of a fishing partner, or by wrapping the line around a smooth pole and handling longer lengths by yourself.

Your leader can ve straightened by running it through your hands. The heat generated by pulling the leader through your hands will straighten the leader. Do this carefully so as not to burn yourself.