Those flat "no kerf" trimming saws are nice for things that really poke out.
You may not have that...
I sometime put a wad of duct tape on a file for rough work so I can get close to a surface without scaring the wood where the pointy end of the file rests.
After that a plane is nice... Or a sanding block. (Some why to keep a crisp edge.)
Or the edge gets a chamfer or a a small radius later, but not a taper like the old maps of the earth with ships falling off.