The adjectives that come first are more about relating or differentiating from other similar things (often: opinion, size, and age). The adjectives that come last are providing details about what it is (often: origin, material, and function).

For example, “the best American short stories”.

But hang on, in the example “the best American short stories”, short refers to size, and it is after American, which refers to origin! Even though the rules for word order apply to “a little old American man”, the order is not set in stone. The details that come last are those that are more important for the listener to understand what it is. Being short is the main defining feature of short stories. The speaker basically puts the words that help the listener relate and differentiate first, and the words that help the listener define are last.

Many words provide a combination of both and may be helping the listener relate, differentiate or define; depending on the context or the speaker’s thoughts. So, the order can often be flexible. Both “green rectangular” and “rectangular green” are common, as well as and “big beautiful” or “beautiful big”.

Related:
Flexible Word Order

Looking for a good grammar book?

If you like looking at grammar in terms of meaning rather than rules, check out my book – Real Grammar: Understand English. Clear and simple.