We give:
kitten’s pedigree
Full Vaccination record
Record of worming and flea treatment
Balanced diet sheet and feeding guide
Information about the breed and its origin
4 weeks of free insurance from Pet-plan
Food vouchers
Several bags of free biscuits (at least 2)
Free sachets of kittens favourite wet food
small mouse
kittens favourite toy from playing at our house
membership to the Birman cat club if new owner not already a member
and let new owners know they can call any time for information

GCCF transfer form (pink slip) is sent on proof of neutering.
Microchip (not at present) but I am on a waiting list to do a microchip course and once completed all kittens will leave microchipped

I also like the suggestions about knitted blankets and I have just got back into knitting so thats another item to add thats also personal too.

Love all the ideas though