Some of Ruk’s mobiles made out of plastic bags. These look well inside where the light shines on them or can be used most effectively to scare off the birds outside.
They are made by cutting plastic bags into long strips (cutting round and round, as when peeling an orange) and then simply tying to something that can be used to hang it by. The third photo has the strips attached to a small square of crochet made out of the same strips of plastic.