I think some people are afraid of the high bun. If you're wearing your hair the exact same way every day, it's time to change things up. With all the different variations of the bun (loose, messy, tight, super high, not so high, low), you'll know what works best for you.
Today I was running a bit late, so I went with the high messy bun. To get that messy look with flyaways, TEASE. TEASE. TEASE. And then just throw it up in a bun with a rubber band. Pull on the top sections of your hair to loosen it up and you've created the "Messy, I don't care" look. Funny...you actually do care but it honestly only takes a minute of your time.
I also like to wear my hair in a cleaner version of the high bun. For me, teasing is always involved. Depending on the texture and thickness of your hair, it may not be necessary. If you do tease, smooth out the top layer, throw up in a bun but make sure it's a little tighter than the messy bun. I'm a big fan of a full bun and because I don't have the thickest hair, I have a little trick. I take a little section at the top of the bun and use a bobbypin to pin it to the side of my head closest to the rubberband. I repeat it throughout the entire bun and walah, you have a big bun!
Enough dissecting of the bun! Now go experiment.