I heard from my brother, that he heard from an expert that if you hang FAKE fruit from your fruit trees while they are blossoming, the birds will be faked out. Apparently they try the "fruit" and realize that it isn't a source of something yummy. Then when the real fruit ripens, the birds think, "been there, done that" and they leave it alone.
So I am trying it. I went to the dollar store in search of something fruit-ish. I found mini pumpkins, which are not grown in spring. But, I thought they had the right color. I have a peach tree. So I used twisty ties and attached them to a few branches. I don't know if it will work yet, the fruit is just starting to come on. I'll let you know!