Your friend has been working 12-hour days. [should]
You should take some time to relax.
You want to go out for dinner with a friend, but she is bored of the same restaurants. [ought to]
We ought to try a new restaurant tonight.
Your friend doesn't know how to manage his money. [ought to]
You ought to consult a financial advisor.
Your friend is feeling bored of the same routine. [ought to]
You ought to plan a vacation soon.
Your friend made a mistake at work, and feels bad because they didn't apologize. [should]
You should apologize for your mistake.
Your team has an important meeting today, and yesterday your coworker came to work late. [had better]
You had better not be late to work today.
Your friend is always dehydrated. [ought to]
You ought to drink more water.
Your friend decided to move to a new city with her new boyfriend, but you think she's making a mistake. [ought to]
You ought to reconsider moving so soon!
Your roommate is procrastinating on finishing his assignments. [had better]
You had better not procrastinate on your assignments.
Your coworker doesn't take time to eat lunch - he eats at his desk every day while he works. [ought to]
You ought to take a proper lunch break!
You and your friend are going to the airport, and you want to avoid the traffic. [should]
We should leave early to avoid the traffic.
It's supposed to rain today, and your friend always forgets to bring her umbrella. [had better]
You had better not forget to bring your umbrella.