Messy buns work best with slightly dirty hair that has some texture and grip. If your hair is freshly washed, consider adding some dry shampoo or texturizing spray to give it more volume and hold.
Flip your head upside down and gather your hair into a high ponytail at the crown of your head. Use your fingers to gather the hair rather than a brush for a more relaxed look.
Once you've gathered your hair, secure it with a hair tie. You can wrap the hair tie around 2-3 times to ensure it's secure, but avoid pulling the hair too tight to maintain the messy look.
Gently tug on the hair around the crown of your head to loosen the ponytail and create some volume. This step helps to avoid a tight, slicked-back appearance and adds to the messy, undone look.
Take the ponytail and twist it loosely around the base to form a bun. Don't worry about making it perfect—imperfections add to the messy bun's charm. Secure the bun with another hair tie or bobby pins, tucking in any loose ends as needed.
Once the bun is secured, gently pull out a few strands of hair around your face and ears to frame your face and create a more effortless look. You can also pull out some strands from the bun itself to add to the messy effect.
If you want extra hold, you can lightly mist your messy bun with hairspray to help it stay in place throughout the day. However, keep in mind that the beauty of a messy bun is its casual, undone appearance, so you don't need to worry too much about it being perfectly polished.