I used chunky yarn for the actual hat and worsted weight for the plume. It turned out fine, but Kat used chunky yarn for the plume. I think the chunky yarn may have stood up better, but it still ended up looking great either way (I would still recommend using chunky yarn for the actual hat, though). The plume did take quite a bit of time to finish and I just eyeballed it until it looked about right.
My mom gave the hat to a lady she works with for her grandson (she is a big Spartan fan). Look at how cute he is!
I look forward to making more of these hats. I still have some Star Wars figures to make - 2 exams this week and hopefully after my life will be a little less busy. I am almost done with another hat I started a while ago - I'll post it soon!