The trick is designing something that works, but doesn't look like crap and distract from the appearance of the pond. My pond was relatively small and in a section of my garden with a Japanese style. I made a lattice of redwood 1 X 1 inch stakes, with a square grid pattern with about 6 X 6 inch openings. It had a "trellis" style look to it, and the fish/plants could be viewed easily. It was also large enough to place large stones on the edges that extended beyond the pond, so it looked good and couldn't be lifted by the raccoons. to the underside of the cover, I later added the black netting with approximately 1/2 squares used to protect fruit trees and such from birds. It was quite affective while still being attractive and allowing free viewing of the fish.