I know that おやすみなさい means "good night" in Japanese and it can be shortened to おやすみ. What is the difference between the two?
In English there are other phrases such as "sweet dreams" that can be used with a similar meaning. So are there any other common ways of saying "good night" in Japanese?
Background. I would like to get a tattoo that says goodnight because I have insomnia, and I want to get a tattoo that says goodnight in Japanese. I'm not really knowledgeable when it comes to Japanese but I would love to learn it in the future and this might be my gateway into learning Japanese more.