Eyelids... hoping to convey a groovy mood.
For whiskers you could use a bit of stiff fishing line... or you could extrude a bit of filament manually from your 3D printer. Dab the end in a bit of school glue and poke into place.
Ears were difficult for me... my first attempt looked like bunny ears. Second attempt looked like something you might find on Piglet. Finally, I added a pinch of white on the interior of the ear to give it a little shape - and called it done.
I added some tufts of felt on the cheeks which turned out nicely. Anyone remember Bill the Cat?
If somone just walked into the room at this point and said, "awwww!" You're on the right track!
Not part of my original plan, but I'm going to load-up the front feet with a few beefy washers to keep them from flopping around as the tail wags back-and-forth.
If you're [ pick one or more: obsessive, compulsive, picky, detail oriented, excessively caffinated], you can cover the ugly with a bit of felt sheet.
As well as the base, for ultra-fuzziness!