1. Tell the neighbors directly and euphemistically.
Direct communication is the best way. Just gently remind your neighbors, or if you feel confident in your language skills, you can beat about the bush without hurting your feelings at all, unless your neighbor is a particularly stingy and unreasonable person.
2. Cut a plate of fruit and go to the neighbor's house.
Cut a plate of fruit and go to the neighbor's house. Take this opportunity to chat and remind your neighbors that it interferes with your life. As long as you treat each other with courtesy, the other party will not put on a bad face.
Write a note to tell him (her)
If you don't want to communicate directly with your neighbor, you can write a note and stick it on your neighbor's door. For example, your neighbor always throws garbage into the corridor, which makes the corridor stink. If you don't know how to say it, leave a note for your neighbor to remind you gently.