craftgrrl | Smaller skully issue

I posted my little skully cake creation on Craftgrrl a couple days ago, and was so excited and grateful for all the positive feedback that I have now started onto my next idea of making them smaller keychains! BUT.. I have ran into a little snag :( (no pun intended)

I'm trying to figure out how to do the lines of the cupcake cup on the bottom. On the bigger model I used little strips of felt, but with these newer ones, they are too small to cut felt to the width it would need to be to look proportional. My idea was to use lengths of twinned embroidery floss, but it's not turning out the way I want it. :( It's coming unraveled and pulling too much on each end of the felt, kind of making it curl. My only other option I can think of is hand sewing smaller lines with smaller stitching. Was I maybe using the wrong kind of string? Would a more tightly wound string work better than the embroidery floss? Sorry if I seem life noobish at this. D: Thanks in advance!

Floss unraveling :(