Bushes? Edibles such as raspberries, Saskatoon, Gut Cherries, Honey berries etc. Might attract bugs though.
Another option might be frosted glass panes installed via railing?
http://www.calgaryrailings.com/glass-railings-calgary/ (Check the one saying cozy privacy or privacy glass around outdoor patio)
Combination of both? Frosted glass with a Flaming C sticker?