Here are two of my favorites:
君子之交 (淡如水). This doesn't appear to be in CantoDict. The original context talks about how a gentleman's friendship is clear and clean, while a commoner's friendship is sweet and smothering, but that's not how I've heard it used, or how I use it. I've heard people use it to describe a weak and flavorless tea. It literally means "A gentleman's friendship (insipid like water)". This is just a funny and sardonic way to describe the tasteless tea. "It's like a gentleman's friendship".
明師出高徒: "A great teacher will produce a good student." This isn't really a 成語, especially since it has five characters, but it's a nice set phrase that you can use when being complemented by or in the presence of your teacher, to shift the praise onto them. 明師出高徒啫嘛.
君子之交 (淡如水). This doesn't appear to be in CantoDict. The original context talks about how a gentleman's friendship is clear and clean, while a commoner's friendship is sweet and smothering, but that's not how I've heard it used, or how I use it. I've heard people use it to describe a weak and flavorless tea. It literally means "A gentleman's friendship (insipid like water)". This is just a funny and sardonic way to describe the tasteless tea. "It's like a gentleman's friendship".
明師出高徒: "A great teacher will produce a good student." This isn't really a 成語, especially since it has five characters, but it's a nice set phrase that you can use when being complemented by or in the presence of your teacher, to shift the praise onto them. 明師出高徒啫嘛.