BE TRUE TO YOURSELF
What makes a great image? Anything you say it does!
There are no rules. It's all in the eye of the beholder.
When you get good, the only eye that matters is your own. No two eyes see the same. Your vision needs to be true to yourself.
It's OK to solicit comments and suggestions when you're first learning. This helps you master the basic technique. Mastering technique frees you to create. Mastering technique gets it out of the way of your creative process.
Photography is taking an image from your mind and fixing it in tangible form. These images may be real or imagined, and the tangible form is usually a printed photo.
Anything that comes between your imagination and the final result needs to get out of the way. Cameras, lenses, HDR, profiles, focus, sharpness, pixels, etc. are all crap. They have nothing to do with photography. They just get in the way. When you master technique you can see straight from your imagination to the finished work. Then you are free to create great images.
Follow your own imagination and vision to create great images. Show what excites you. Show what consumes you. Show what makes your life worth living. Show what you love. Show what you hate. Show what's important - to you.
Don't follow the crowd and make the same technically perfect, but completely forgettable, images. Show what you care about. Let your work consume you. Let it drive every aspect of what you do. Live for it. Share it. Die for it.
When you die, do you want your kin to be arguing over who has to haul your life's work to the dump, or arguing over who owns the rights to it?
Be bold. Be crazy. Screw what people think. Drill your own hole.
Everyone says this. Stieglitz was one of the toughest judges and gallery owners out there. Even he said: "Should anyone want to go to his own particular photographic hell in his own particular way - manipulated, hybrid or whatnot - I say 'Go to it!' But go to it for all you are worth, the harder the better, insisting on your right of way without necessarily disregarding all traffic lights. And if you must disregard even these, I say go ahead full speed!'" (Aperture Masters of Photography - Alfred Stieglitz. Publ. Konemann, Cologne, 1977.)
If you find this as helpful as a book you might have had to buy or some lame motivational workshop you'd have been too embarrassed to admit attending, feel free to help me write more with a donation.
Thanks for reading!