Congrats on your double delight Molly! And great on already having the twin feeding pillow. Sounds exactly like mine. Blue, strap around the back, and back rest. You are def going to need it if you want to double feed (big time saver and great if you can do it!).
Tips- have you got a breast pump? Of not, its a good idea, then you can express inbetween some feeds and get DH to feed one to have the odd break (taking care not to interfere with your supply). Also expressing is good to up your supply especially when the bubs are going through a growth spurt, that sometimes never seems to end! main tip, is to be super organised. Accept help if you have any around, do your best and also try to relax and take everything in. Its so easy to get lost up in everything.
Oh, and try and get as much sleep before they come!!
xx