I agree with all the above.
I had emergency section, but really it was fine.
Yes yes yes shave/trim yourself. I had more irritation from the urgent Bik-no foam scrape than I did from the actual wound.
Asda cheapy cheapy pants two sizes too big (as you put it for that lovely Simon Cowell look) comfy for the scar and then you can bin them guilt free. Lochia is just annoying whichever way you deliver.
Flip flops for the shower so you don't have to attempt to bend down.
Masses of food you may actually want to eat - a minor thing, but being trapped in hospital for the extra tme is really quite tedious.
Pillows - yes take your own as a home comfort. There should be loads of help to bf - V-pillow def comes into its own after CS. Ask to be shown rugby ball position (on the links someone else has posted above).
Something to do/read - remember you won't have the exhaustion from a vaginal delivery so there is a strong liklihood that just because baby is asleep, you won't be, and you can't have visitors at all times. That said, motherhood dictates it is entirely possible to spend an hour or more just looking and marvelling at the little one!
Good luck.