I asked my hair stylist what the best volumizing hair spray is. She said that there are many good ones but told me to stay away from those that contain PVP. I found out that PVP stands for polyvinylpyrrolidone. Apparently, it's a type of polymer that's harmful for hair. My stylist recommended a product that's made of vegetable gum and herbal extracts instead.
It's kind of expensive though, so I might make my own volumizing hair spray. I got the recipe online, it just requires lemon and water. I'm going to boil lemon wedges in water and use it as hair spray. It's supposed to add volume to hair. I hope it works!