How can I decorate the side of a 12ft storage shed in my back porch?

Could you finish your question..........

If you want it to blend, I painted mine same colors of the house, I find it doesn't stick out like sore thumb anymore then when it was just the natural shingles, but once you do it then you have to repaint every 8 years or so.

Are you crafty? After the surface has been prepared, t he wall could be painted; flowers, barn or meadow setting, painted to resemble and open green house with blooming flowers inside, a tree off-center to one side or the other with blooming flowers with your pet painted in, just used your imagination to paint whatever is appropriate for your site or what you might prefer. Another suggestion would be to paint the entire wall a solid color and paint one of the "barn quilt" in a pattern you like in the center. It's easy to google for quilt patterns. If painting the wall is out of your skill set, contact the art class in your local high school. Ask if they are looking for a "project" for the current school year or the next. If you know a budding artist, they might be agreeable to using your site as a means of getting more exposure for their craft. You might want to contact a senior's center near your location; the seniors are there usually for contact with others and might be interested in tackling your project. If they happen to not be "painters", remember it doesn't have to be perfect to be pleasant to viewers and fun for the partcipants.

Of course there is always paint! Possibly a grass fence might work, if there is room, then you decorate it if wanted.

Without a picture or complete question, it's difficult to comment. Is the shed next to the house or in the back yard? I'd go with creating a focal point. Like a she shed or man cave. Paint it a bright color, create a mulched bed around the base with potted plants. Your shed, your design. Have fun and enjoy! Go for it!

Place shutters with a window box, if no window then use a window pane with multiple panes and use murcry glass spray. Add a bench with a footed flower urn then add a trellis.