When you are writing your brief you are making a legal argument. This is a special kind of argument that is very different than day-to-day arguments with non-lawyers. Justice Scalia and Bryan Garner note the objectives of such an argument in their introduction to Making your Case: The Art of Persuading Judges.
Judges can be persuaded when three conditions are met:
This kind of argument can be difficult for even experienced attorneys.
The following books are also useful guides to methods and techniques of effective legal arguments.