If there is one thing that is really cheerful in the world, it is cheerfulness. I have noticed it often. And I have noticed that when a man is right down cheerful, he is seldom unhappy for the time being. Such is the nature of man.
Avoid the unhappy ending, the harsh, the brutal, the tragic, the horrible -- if you care to see in print things you write. (In this connection don't do as I do, but do as I say.