I didn't write a birth plan but I made sure that DH and I had chatted about various things to do with labour. I also told him that I could very well change my mind once I got in there.

For example, I definitely didn't want pethindine, I would go straight for the epidural. I also wanted oils burning and music playing, basically go with the flow and the midwives were very accomodating.

Also being clear about visitors, not only after birth but also during labour, I didn't want anyone visiting but they let my MIL in! I was quite annoyed as I only wanted DH and midwife there. Found it really hard with her talking all the time and that's what she did - talked about crap. DH knew what I was feeling and gave her a job (went and checked on our pets) and then told her to shut up when she come back.

Also find out if they have students at the hosptial so you don't get a shock when you go in. My hospital was a training hosptial for nurses and midwives so if you don't want them then make sure they know about it.