Managing patches? Try quilt. Here is a tutorial.
The basic idea:
quilt new mypatch.patch
quilt add path/to/existing.file.i.will.change
touch path/to/new.file.i.will.add
quilt add path/to/new.file.i.will.add
Then, change your files. To get the patch:
quilt refresh
Your patch will be “up one directory” in a directory called “patches.”