If your hair is dry it will have a messier look than damp. Either way works fine and is entirely up to you.
First start by making a ponytail then a rope braid but not to tight and not real loose
Twist your hair to the end and tie off with a band,
Now take the end of the braid and bring it back up to the base to make a loop and hold in place with another band
Take the loops from the rope braid and pin them, and secure with bobby pins.
You can pull out the loops to make the bun messier or pin to keep it neater