Writing is solitary. It's you, the blank page, and your characters. With self doubt taking up residence on your shoulder, constantly staring down your work, sometimes it's hard to believe what you're doing is worth while. This can't be explained to someone who doesn't write—trust me.
I discovered the best advice comes from writers themselves. Here are a few of my favorite quotes. Hopefully one will kick the self doubt off your shoulder.
“First, find out what your hero wants, then just follow him!” Ray Bradbury
“I have been successful probably because I have always realized that I knew nothing about writing and have merely tried to tell an interesting story entertaining.” Edgar Rice Burroughs
“It is perfectly okay to write garbage—as long as you edit brilliantly.” C.J. Cherryh
“A writer never has a vacation. For a writer life consists of either writing or thinking about writing.” Eugene Ionesco
“I try to create sympathy for my character's, then turn the monsters loose.” Stephen King
“A science fiction story is a story with a human problem, and a human solution, that would not have happened at all without its scientific content.” Theodore Sturgeon
“As for the adjective, when in doubt leave it out.” Mark Twain
“The only thing that works with writing is that you care so passionately about it yourself, that you make someone else care passionately about it.” Judy Blume
“Number one rule for fiction: Coincidence can be used to worsen a character's predicament, but never to solve his problems.” Vivian Vande Velde
“Good stories are not written. They are rewritten.” Phyllis Whitney