Within a category (brand & special category), you can change the 'Display Order' to manual. This will then enable you to sort the products for that category into your chosen ordering.
Edit the category you wish to amend and from the 'Display Order' menu, select manual and update the category.
Click on the magnifying glass for the chosen category to reveal the products assigned, you will now see on the far right green arrows. By clicking on these you can now move your items to their desired position.