- You can ask that if you see someone is kind of down and looks sad, other than that its just a simple Hello.'
- There is nothing wrong with the phrase, but it depends on how people react to it. I think it would be good to ask when the person is in a good mood and that way the person may tell more or at least smile.
- Anytime is a good time to ask a person how they are doing. Generally if you meet a person that is a very normal question to ask and they may respond back and ask you the same question. If someone is depressed or has lost a loved one it's a kind gesture to ask the person 'How are you doing. Is there anything I can do to help.'
When you genuinely sense a person needs encouragement and went to throw them a rescue line.
Personally, there's never not a time to ask how someone's doing. It's a common question, and there's nothing really wrong with asking it. It's no different than asking
'What's up?", so really you can ask it whenever.
