1. Take a picture
Sometimes there will be a moment or so of beauty that you would love to capture in a picture or art but just can't. Try to snap a photo and capture the moment for future reference. Even if the picture is blurry or not exactly as you imagined, you will have a jumping off point and can even search the internet for similar poses to inspire you.
The world isn't perfect so you have no reason to expect it from yourself! As imperfect as it is, the world is full of beauty and the occasional mistake can add to the beauty of your art. I find that the more I try to make a stroke of a pencil or dab of paint perfect, the more it becomes rigid and the picture less real. Don't be afraid to fix mistakes but don't be bothered by a misplaced speck either.
3. Learn from observation
Everyone can teach you something. Even a child might have a different way of looking at the piece than you do. Being teachable and open to other's advice on technique and style can give your art the extra brilliance that makes it inspiring.
4. Be yourself
Though slightly counterintuitive, if you are happy with your piece, don't change it to fit other people's standard of beauty. Art is subjective and if you have expressed yourself the way you had hoped, there is no need to change it to make someone else happy. You cannot please everyone and you might as well make your art your own.
5. Enjoy it
Art inspires thought and gives pleasure. Though it is often hard work, completing a project is so rewarding and your horse will love it no matter what!