I've been wearing my hair this way a lot lately - it's just so darn hot, and this keeps my hair up and out of the way. And it's easy.
Everyone has different hair types, but this is something that I think could work easily on thick or thin hair (I have thin). I've done this with both clean and dirty hair, straight and curled hair, and it's always ended up looking roughly the same. I have long-ish hair right now - just past my collarbone - but this is a look someone with shorter hair could do as well.
First, I tease the crown of my hair a bit because it's so thin. Then I start taking small sections of hair along my hairline and twisting them over each other, away from my face. I keep them a little loose so that there's some volume. When I get about eyebrow level, I pin the twisted pieces, making a little "x" with two bobby pins. Then I loosely twist the hair behind my ear and down the nape of my neck, then gather all of my hair into a ponytail.
Then I make a braid right behind my ear, and tie it with a clear elastic. After that, I'll fluff up the braid a bit, loosening the pieces with my hands. Sometimes I leave it at this stage, and it's a cute, casual look.
What I've been doing is taking the braid and looping it around itself in a bun shape. I tuck the end of the braid up underneath, and pin all around. With my hair, pinning it into a bun pushes everything up and gives my crown some more lift (love that). I also tend to hairspray the twisted area along my hairline and remove the "x" bobby pins so it looks a little nicer. Totally up to you. I wore my hair like this recently to a wedding and it was perfect.
I've also done the braided bun trick with my hair directly in the back of my head and a middle part. Also cute!
I found this trick from Gal Meets Glam and adjusted it a bit to fit my hair type/length better. Thanks, Julia!