I have no accessories other than a 12 South Book Book case. I really like the case, but it's becoming less useful. I had too many plastic cards in it, and it looked like a George Costanza wallet. I've tried to cut back on the number of cards, and the pockets are too loose to hold them securely. If I don't pick up my phone carefully, cards fly everywhere.
Honestly, I was looking forward to September as an excuse to get a new case. I'm waiting to see whether the dual camera is coming this year. That will heavily influence my decision.
True Tone sounds nice, but if it really makes a big difference, maybe I'm better off without it. Next year could be True Tone OLED. Waterproof sounds nice, but I can risk it until next year. I want 3D Touch, but I don't have it on my iPad Pro 12.9", so maybe I should stick to the old 2D touch for another year.
Apple could surprise me, but it looks like dual lens camera is the killer feature for me. After crushing my hopes yesterday, this article says it's back. So, yay!