I'm just going to add on about using a fur texture in case you don't know...
You can use any fur texture you want as Arctic stated. Just bring it into your preset's GIMP file as a new layer and set it to Multiply for layer mode. It should then become an overlay on your preset and give it a "fur" appearance.
There are also some tutorials on YouTube that go over preset making, even for special presets that are asymmetrical or have glowing markings. Just look them up in case ya get a little lost floof.