I had an idea

[Quirk]

Ok, so you know yarn tails? Well, I've made a few of those. But, my new-old idea?
Yarn ears. You know how you can never get your yarn tails to match your faux fur ears? Well, I have invented a technique.
Allow me to explain.  You cut out a base shape of thin foam for your ear. Cover the side that will be the inner ear in a fabric of your choosing. Get little tufts of yarn, just like for a yarn tail, but smaller, and brush them out. Hot glue them to the non-fabric side of the base. You see?

Anyone think this is a good idea? Or is it just me....

[Amducious]

I'm not interested in yarn stuff, I'm more into semi-realistic and realistic. If you want to do it by all means go ahead and see if it works, then post some pictures 

[Timberwuff]

Yarn tails actually give a very realistic look, albeit limp.

Anyhoo! That sounds like it could work well! Sounds difficult too. I'd love to see a sample if you give it a try.

[Quirk]

I should have some done shortly - but at the moment I'm a bit busy with a cosplay for a local con.

[Old Rabbit]

You could use a scrap of your suit fur, but the yarn sounds good especially for long tuffs. Cheaper
than buying long fake fur for sure. Might check yard sales for toy animals or fuzzy coats. Would make
a good source for small amounts of long fur

[Takanuva]

What if you cut the yarn fur into short lengths, sprayed spray adhesive on the outside of the ears, and applied the loose fur with a model train static grass applicator? Then repeat the same step for the inside with a different color, and you should get some nice realistic lightweight fur suit ears.