There are the bird spikes....... the birds will bend them and/or use them to make their nests so you are helping them sometimes.
The electric strips...... the birds will crap on the strips until they are covered with poo and then no more shocks.
Bird of prey sounds.......birds crap on the speakers and chew on the wires from where the sound comes out until it does not work.
The nets seem to work but sometimes hard to install depending on the location. On a covered play area they had me pressure wash the beams, floors and anything else that had bird droppings. They installed hanging nets with small openings for the lights then positioned the nets above the lights so they would not burn. Anywhere they could not hang a net, they installed chicken wire or expanded metal to keep the birds out. This has worked for the kid's play area now for over 1 year now, no more birds.