I parted my princess's hair diagonally across the top into three large sections and left two small ones on the sides.
I made the french knots by tying the hair like you would a shoelace, after each tie, I'd grab another little section of hair and tie that in working myself from the front to the back.
After I finished each row I bobby pinned it in place for the time being.
I pulled all of the hair (minus the side sections below the french knots) into a pony tail and then removed the bobby pins.
Then I did a small french twist with the little side hairs on each side and continued the twist to the end.
Then I used another elastic around the pony tail - pulled the hair half way through and used a second elastic to help shape the messy bun. Other than the bobby pin showing in this picture, I really like how the messy bun turned out.