I think your pigs look cute. I don't feel they need the detail that you're stressing out over with satin stitching. Tail, yes. How.... I tried to look up pictures of pig tails. I think this one looks best, but other than a back stitch (like one that would be used for cross stitching), I can't think of any other way to do this. I think marker would be to the detriment of what you've completed thus far.
http://i.ebayimg.com/t/PORTER-PIG-MA...LOCK-AZEB-/10/!BhlT42QB2k~$(KGrHqYOKj4EsD))VVgKBLJyPERe8Q~~_35.J PG