We have performed some preliminary tests with makeup and blocking of certain regions of the face to see how well we can avoid having our faces detected by OpenCV. The following techniques have proven most successful:
Cover one eye socket:
Cover entire nose up to forehead:
Cover bottom left or bottom right quadrant of the face, covering part of the nose and mouth:
Increase asymmetry of features on your face
Obscure certain facial areas and features. (See above)
Minimize the difference between light and dark regions of your face.