For a flip cover, I got some conduit and bent it into a rectangle then tacked it together. Zip tied a welded wire mesh to the rectangle. Then used conduit holders that were a little oversized to mount it to the front of the blind but not be too rigid when we flipped them out.
Worked great and only cost a few bucks each.
Then God said, "Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, and over all the creatures that move along the ground."