Best tip I was given was to buy a pack of mens' undies. They have more room in the ... er ... crotch so fit pads better.

Definately pack a lovely shower gel - even now when I shower using the same scented one, I can remember Pip's birth.

I also packed 2 boxes of cadbury Roses for the midwives (figured if they were nasty midwives I'd eat them myself) and thankyou cards to give to the staff.