I put this reflective tape on the motor arms on the side facing rear. Now when my Mini is just a tiny black speck in the sky, or I lost VLOS I just hover and slowly rotate and watch for the bright daytime strobe effect. Works very well, AND I know it's orientation.
I also put it on the top to keep the birds away. So far so good.
I also put it on the top to keep the birds away. So far so good.