Giant sanitary pads to pop over the wound, big knickers to hold it all in place and not rub.
my NCT (birthing) group suggested buying a large pack of men's boxer shorts from Primark (cheap UK clothing store) but I ended up getting disposable stretchy panties from Boots the chemist. Maternity pads were a MUST! I was doing daily walks as gentle exercise but found that I would bleed slightly heavier after the walk finished, so I went through many.
Not a "pretty" gift to give, lol, but I ended up giving a few unused packs to my friend in hospital who ended up having an emergency c-section (along with a couple of fully-front-opening nighties) - she was there for a week + so appreciated these useful + urgent items as they were not things that they had planned to buy! I also had a spare baby bodysuit (long sleeves, closed toes) and gave that to her as she was told that they could not move their baby out of the ward unless he was dressed like this (??? odd) - she only had short sleeved baby suits.