How far off from the wedding date should I start looking for dresses?

I have no idea when to start looking for my dream dress. I'm someone who is well organised and ideally I'm trying to have everything for the big day sorted 12 - 8 months prior to the date however I'm stuck on when to start looking for my dress. I'm worried that if I leave it too close to the date then I'll stress out and rush the process and then on the other hand I'm worried I pick too early and want to change the dress.!! I might add that I also hate shopping and can never decide on things from clothes to dinner ha! Any tips would be greatly appreciated.