Every year I meet with a bride who tells me that she absolutely loves hydrangea (just for example), but her best friend just had/is going to have hydrangea at her wedding so she doesn’t want to “copy”.
While I understand and respect this sentiment–I have a younger sister so copying/borrowing style was a sore subject in our pre-teen years until she decided she had zero interest in “my style”!–but, I think when it comes to your wedding the only thing that matters is that you get what you want. Just because your BFF is getting married a few months before you doesn’t mean that your wedding will be an imitation. Side-note: copying your friend’s wedding style on purpose is extremely lame, however.
If you truly love a particular flower or venue or band or photographer who cares if your friend has it, too. If it suits your style, budget, season, etc. you should go for it. It’s your wedding, you can do what you want to.
Above: Two shades of purple hydrangea with thistle in a ball jar. Simple.