Whenever I see someone who looks down, I always want to go up to them and....
But....HOW DO YOU DO THAT?!?!??
First Step: Find the Reason
Ask the person how they are doing and what is bothering them.
Find out the reason of the poopy look on his/her face!Second Step: Talk it Through
After finding out the main reason, talk through the problem with him/her. Let him/her tell you the story and listen well. Comment on what he/she is saying.
Third Step: Opinion
Give he/she your opinion on the whole situation. If you agree to what he/she is saying, tell him/her.
If you disagree to what he/she is saying, let him/her know, but not harshly! Use a comforting, soft voice.
Fourth Step: Advice
After letting him/her know your opinion of the story, give him/her some advice to solve the problem.
If you have agreed with him/her, just put yourself in his/her shoe, and ask yourself what you would do to solve the whole problem. After you think through the solutions yourself, tell him/her.
However, if you have disagreed to what he/she had said, give him/her some good advices to help him/her right him/her own wrongs. While you are giving advices, you may use the words: "I think you should..." or "Maybe...".Fifth Step: Summary
Give him/her a simple summary of his/her situation. Make it simple and don't make it sound complicating!
Remind him/her the advices you gave him/her. Tell him/her that it is not a big problem at all, and that he/she should just relax and fix it without any sweat.

:) :) :) :) =) =) =) =)