If your hair is in the thin to normal range you can enjoy the benefits of a 100% boar bristle brush. For shoulder-length or longer hair, you'd do best with a Large Extra or Small Extra.
You could also be well served by a larger mixed bristle model, the Popular or Junior. They offer the benefits of the pure bristle models at a considerable savings.
If your hair could be described as "fine, but a lot of it", go with the Popular or Junior. You will need the stiffer nylon bristles to reach your scalp.
The Handy or Pocket versions of the recommended brushes would also be suitable, but we recommend the larger brushes for this length.
If you haven't yet had a look at our full Brush Guide, we recommend doing so.