When it comes to organizing and keeping things tidy, the phrase "neatly stacked" comes to mind. However, if you're looking to add some variety to your vocabulary, there are plenty of other synonyms you can use. For example, you could use "well-ordered" to convey a sense of neatness and precision. "Tidily arranged" is also an option, indicating that things are neatly put in their proper places. "Systematically filed" suggests a logical and organized system of stacking, while "neatly piled" conveys a sense of height and stability. Overall, there are many ways to describe orderly and tidy stacking, so don't be afraid to mix it up!