I made this for a costume contest at a Mardi Gras Rocky Horror Show at the theatre I work at. I ended up not entering, but it was still a really fun project.
First, gather all of your materials. Let me note that I used a white mask base, hence why I needed the black paint. If you use a black mask base, you can skip the painting step.
Glue the feathers onto the plastic mask from the edge of the mask inward, letting the layers dry as you go. You can use a dot of glue under the feathers to make them go the direction you wish them to. Try to make a pattern out of the colours you use (even though my step-by-step pictures are terrible). Let everything dry for about 15-20 minutes.
Glue the black cording around the edge of the nose/beak and around the edge of the eyes (see red marks), making sure not to cover up your eye holes too much. It's okay to let some of the mask show around the eyes, we'll paint it later. Make sure to let the glue on the cording dry a bit.
Glue a bit of rhinestone trim onto the feather "seam" in the middle of the forehead. Now you can separate part of the rhinestone trim by pulling the edge off of the rhinestones themselves. Use the edge to line where eyelashes would be, and the single rhinestones at each of the corners of the eyes (see the yellow marks). Let the glue dry a bit.
Now you can paint the nose/beak and the inside of the eyes (if necessary). Use a few coats to get it covered well. You can use a varnish to gloss it up a bit. Let everything dry completely.
Attach a dowel either by using your E6000 or some masking (or similar) tape, and you're done...