I fashioned my birdcage veil from components of a beaten up vintage hat I scooped out of the free box at a thrift store. I know the above "before" photo of it makes it look fairly decent but trust me, a scrunched up white hefty trash bag on my head would have looked better.
After searching a bit on the nets I located a simple birdcage template:
I cut the veil part away from the old hat (the only salvageable piece) and loosely followed the above design.
I attached the cinched veil to a little piece of craft foam covered in a piece of scrap wedding dress material. Under this, I glued a little hair clip so I could attach it to my noggin. I then topped it all off with a black velvet bow....helped to hide any possible flaws!