1. “You look tired.”
What you're saying is they look unappealing or grouchy. Try saying "Is everything okay?" if you're genuinely worried about their well being.
2. “Wow, you’ve lost a ton of weight!”
This suggests they used to look fat/unattractive. Try replacing it with "You look fantastic!"
3. "You were too good for her anyway.”
We know you want to help your friend get over a breakup, but questioning their taste and judgement for getting into it in the first place is not the way to go. Try "Their loss!" instead.
4. “You always…” or “You never…”
These phrases make people defensive and shut out your message
5. "You look great for your age.”
No need for the "for your" qualifier, "you look great" will do just fine!
6. "As I said before..."
This phrase makes you sound condescending and as if you're insulted you have to repeat yourself.
7. "Good luck."
This phrase implies that they need luck to succeed, instead try a positive "I know you have what it takes!"
8. “It’s up to you.” or “Whatever you want.”
Your opinion matters to whoever posed the question, so by blowing the decision off it's like you're rejecting them too. Try “I don’t have a strong opinion either way, but a couple things to consider are…” next time.
9. “Well at least I’ve never ___.”
You're probably passive aggressively reminding your friend of their mistake rather than owning up to yours. Take responsibility with a simple "I'm sorry" so you can continue to work through your issues.