It is possible this is the easiest hairstyle ever; all you have to do is wakeup and follow these tips:

First: Come as you are
Got natural waves or curls? Keep them! Use your fingers to work out tangles, lightly tease your crown with a comb and then let your texture take over.
Got straight hair? Spritz on a wave enhancing spray and scrunch before teasing.

Second: Twist up the back
Gather hair at your nape, and then loosely twist and pin it all into a bun. (Or do a topknot). If you have a bob, tuck and roll your hair up in back, pining as you go. Gently tug out front sections.

Last: Let go!
Finish with hairspray but don’t OD. You want pieces to fall around your face as the night goes on.