Used to give advice or recommendation after a past-tense verb: “you'd better ~” or “it would be better to ~.”
早く寝た方がいいですよ。明日は早いですから。
You'd better go to bed early. Tomorrow is an early day.
その本は今買った方がいい。値段が上がるかもしれないから。
It's better to buy that book now. The price might go up.
風邪がひどくなる前に病院に行った方がいい。
You should go to the hospital before your cold gets worse.
分からないことは先生に聞いた方がいいです。
If you don't understand something, you'd better ask the teacher.
Used after a negative verb to recommend refraining from an action: “you'd better not ~.”
今はお金を使いすぎない方がいい。
You'd better not spend too much money right now.
雨がひどいから、今日は出かけない方がいいよ。
The rain is heavy, so you'd better not go out today.
その話は今しない方がいい。相手の気分を害するかもしれない。
You'd better not bring that up now. It might upset them.