Take your camera, be it a DSLR, a point and shoot camera, or your cell phone. Take ten photos a day for a week. Every day, select just one to keep. Every week, select one of those "finalist" photos to keep.
This will help develop your selective eye for judging quality works. Drawing or any other medium can be reasonably substituted for photography.
Even though Vincent Van Gogh is regarded as a master draftsman, he doubted his own drawing abilities, considering it "impossible and beyond my abilities,[1]."
