For not so deep sad feelings, I suggest the homeopathic therapy: turn sadness into melancholy with the help of very good sad songs or songs with a deep meaning; suggestions about the singers: Leonard Cohen, Nick Cave, Fabrizio de Andre`, Ivano Fossati. Then breath deeply and try to plan something that will keep you busy. Deep sad feelings in my view need a human being around, and maybe even a good therapy; this unless they have an immediate cause, like a big change in life, something bad happened, in this case the passage of time or counter-action within the limits of the law would do.

Good suggestions ! all are my favorites ! yes ,think towards this direction !

when i'm sad i usually take my mp3 with my favourite songs ang go walk on the evening streets. i sing, make strange photos, drink something, thinking about whatever...it's just time for me...

you remember all the good things in life, and be thankful for what you have

listen to the music ,no thinking.