nothing new under the sun I'm afraid.
I've been doing that for 30 odd years.
Was doing it yesterday.
best way to throw stuff for dogs is to first get the dog running so that you know where to throw the ball.
Plus a fake throw gets dream to drop the tennis ball and go after the invisible one so I can pick up the real one.
Mostly phoebe steals it off him and I'm getting her to bring it to me with scooby snacks
Given that she will steal ANY dogs ball or toy - being able to get her to brig it to me is quite important lol
I also tend to warm up with an empty sling and practice new styles with invisible slings.
My m,ain warmups at the the competitions are with an empty sling.
Hell even a throw with an invisible sling gets the dogs looking.