Humor and comedy are hard to write well. And yet...

...if you make the readers laugh, they'll forgive you all your other lapses, so focus on it. 

Have a character who provides comic relief. 

Have your characters joke. 

Make your descriptions of things funny with hidden humor. 

Find a way to make the reader laugh.

Your reader will keep reading. 

(Check out the very opening of A Game of Thrones, the first book, A Song of Ice. Not only the dialogue but every word drips with such clever, quiet humor that you can't help but snicker and read on, and on, and on.)

Gif by Jay Quercia