When you know your work sells, then seeking a gallery or outdoor show is fine. Then, if an event or art gallery kicks sand in your face don't give up, keep moving forward. Use your brain and eliminate a lot of your personal agony. There are times when you should not take NO for an answer. But there are others when you should never put yourself in the place to be rejected to begin with. Seek the wisdom to know the difference and then go for it. Persevere in the face of disappointment.
