What are the rules in Chinese for adjective order when multiple adjectives describe a noun
There are a few general points on the order:


words with two or more characters should be further away than single character words
phrases/words ending in 的 should be further from those without
the type/class/make/category of the described noun should be right next to it


For example:


漂亮的 (adjective pretty) 新 (adjective new) 丝绸 (dress' type silk) 晚 (dress' style evening) 礼服 (noun dress)
新的 (adjective new) 漂亮 (adjective pretty) 丝绸 (dress' type silk) 晚 (dress' style evening) 礼服 (noun dress)
丝绸的 (adjective silken) 漂亮 (adjective pretty) 新(see note) (adjective new) 礼服 (noun dress)
丝绸的 (adjective silken) 漂亮 (adjective pretty) 晚 (dress' style evening) 礼服 (noun dress)


Note: Avoid putting two single character words next to each other.

Note Two: Actually, avoid squeezing so many adjectives into a sentence in the first place.

The question's example of 又新又漂亮 is an entirely different situation. That's because it is using the syntax 又 X 又 Y.