A `git format-patch` attached to an email is easiest to apply
and test locally.
Generally emails would be more verbose when discussing patches.
As for the commits themselves my rule of thumb for the commit message is:
reason for change limited to 70 chars or so (the why)
Optional short paragraph giving an overview of the change.
Usually this is only included for new features / substantial changes,
that require some context.
* file_name_1 (where): what has changed (the what)
* file_name_n (where): Likewise.