I almost didn't include this hairstyle, because I was stuck thinking of it as "Gibson Girl," which is, you know, entirely the wrong era. But then I wore it for one very long rehearsal, by the end it was mostly fallen out, and I realized that if you do it loosely it really fits the Elizabethan shape! It almost looks like you're wearing a snood. Plus, it's incredibly, deceivingly easy while looking fantastic.
Here's the lowdown: you need a circlet, but after that you're set. (This is my go-to hairstyle lately.) Leave all your hair down. Place your circlet on top of your head and twist the front sections under as in my Twisted Circlet hairstyle. Then you just tuck all your hair into the headband, use some bobby pins as necessary to tuck up strays, and voila! The trick to getting this more Medieval look rather than something more modern is to tuck the hair all the way around, rather than just in the back.