I am awful at doing hair, but I just mastered the donut bun and I am so proud (prouder than of my degree, my DS, professional achievements
I am actually joking for those who've had a sense of humourectomy....)
Anyway. Hair in a low ponytail. Slide the donut over and pull it out to the end of the tail. Then tuck the ends of the tail over and roll the donut down the hair - there will be ends sticking out but that is ok!
When you get to the point when the donut is at your head (hope this is making sense), take another bobble - here I use an extra long one - and put it over the donut, pulling in any loose ends. Then roll the donut again, so the second bobble and ends are tucked away inside.
Finally, take one more bobble and wind it around between the bun and your head, for extra security.
Your hair sort of expands all the way around the donut as you roll IME, but grab a mirror just to make sure it's all covered. Then hairspray.
Thie has survived a full day of outdoors dog and preschooler wrangling, with a bit of yoga chucked in at the end for good measure, and needed only minimal retooling throughout the day.
It works best on hair that was washed the day before (as will all updos).
Keep trying!