1. Listen to what you've noticed and add a delay to your major decisions about people. This will *not* feel natural. It will feel intellectual and not like a gut choice. You might feel guilty. You might feel like you have to resist something you feel you want to do. That's good because you've already decided that you are not a great judge of character. You're changing that.
2. Make sure you spend some time away from the person you're making the decision about while you make the decision.
3. Watch your cynicism. Never trusting isn't any more accurate or worthwhile than overtrusting. Just take more time.
4. Notice peoples' actions. Do they walk their talk? Do they follow through? Do they at least verbally acknowledge responsibility and mistakes when they were unable to follow through?
5. If someone's talking smack about others to you, they're probably doing the same to you.
7. If someone's cheating on someone else with you, the odds are higher they'll cheat on you (this one never ceases to amaze me).
8. Is the relationship mutually beneficial?
9. Practice telling someone directly what you need from them or what your concern is if you have one. They might not be able to meet your need but should be able to handle relaxed, direct communication. If they can't handle direct eye contact that's worth trying to understand.
10. Are you a bad judge of character or are your expectations based on your own needs and not on the reality of what this person can or has committed to deliver?
11. Watch someone in action: playing a sport, under pressure or in some other flow activity. It's easier to see more of what they're really about.
12. Notice how people treat their friends, co-workers, family and especially how they treat people in different "status" positions and people who are of no apparent "use" to them. Does their behaviour change? 13. If you expect relationships (personal, work or otherwise) to always fail or be unreliable then you might have learned to read your dysfunctional family experience as a truth about everyone. There's plenty of self-help literature, 12 step groups like Al Anon and counseling to help deal with this.
14. Believe what you see.
Inspired by a @ryanomics tweet.