Trust Your Gut

I ignored so many red flags in my twenties. "He's just like that." "She didn't mean it that way." Making excuses for bad behavior because I wanted the relationship to work.

Watch for: controlling behavior disguised as concern, isolating you from friends and family, consistent lying about small things, explosive anger, and disregard for your boundaries. These things don't get better with time - they usually get worse.

Green Flags Too

Also notice the good: Do they respect your opinions? Are they kind to service workers? Do they take responsibility for their mistakes? These matter just as much.