Always search for the source of your feelings
Whenever it is happiness or sadness
If it's happiness you feel
think about it and do it again if it's not harming anyone. ( people around you and of course if it's not hurting yourself )
If it's sadness or or anger
think about it, does it really matter? Is it changeable? Do you really have to feel bad because of it?
But still, emotions they will always be there, even if you know what you are going through.
You will still feel it.
And that is the art of feeling what you are feeling - it is O.K.
It's ok to feel all of it, as long as you don't let it consume you.
Not feeling good is ok.
But try to find the reason why, if there is no reason you will perceive that the bad feeling will slowly fade.
Feel it, don't let it consume you.