[Ankesh]

Interesting question Sandi.

For the most part: I don't give unsolicited suggestions or advice or warnings. They are almost never welcome even if you mean well.

Doesn't matter how well you phrase the warnings. It also doesn't matter if you ask "may I point out something that may be distasteful to you?" first before letting them know about their error.

Most people won't appreciate it.

If the person asks for feedback, then use that chance. Or if you know a common friend, then pass the message via them. But be the direct messenger of unsolicited advice only if you really really feel uncomfortable about the situation and if you don't mind being snubbed.

(For the record: I love unsolicited suggestions and warnings.)