A birth plan is a way for you to communicate your wishes to the midwives and doctors who care for you in labour. It tells them about the type of labour and birth you'd like to have, what you want to happen, and what you want to avoid. http://www.babycentre.co.uk/a544479/writing-a-birth-plan
Some of the things that you can decide such as type of birth (natural/c-sect/water), labor positions, episiotomy, to use epidural or not, cord blood to donate or keep, vacuum extractor or forceps use, to keep placenta or not and etc. These are more common one.
Here are some of the templates for birth plan
that you can fill up and discuss with your gynae. It is best to discuss during in the mid of 3rd trimester. http://www.sassymamasg.com/pregnancy/how-to-write-a-birth-plan-in-singapore/
http://sg.theasianparent.com/how_to_make_a_birthplan_singapore/
For me, I wrote down a list and pass to gynae and go through with her. There are: No episiotomy, drug-free labor (but with laughing gas), donate cord blood, let my hubby to cut baby's umbilical cord. I did mentioned to gynae I wish to have a delayed umbilical cord clamping to lower the risk of anaemia and increases the number of red blood cells in newborns. However, my gynae said it is not recommended as it will cause more serious jaundice in Asian baby.
During the day of delivery, please remember to bring your list of wish (birth plan), so can use it as a reminder to the gynae.