Everyone has already given such good advice. For me, the breathing techniques really helped to relieve the pain, and I found the first 7cm to be such a breeze (in comparison to what I'd expected)
However, I got really tired after that, having not slept at all the night before, and didn't have the energy to breathe properly, and those last 3cm I just kept reminding myself why I didn't want pain relief. I kept imagining my darling DD being born all doped up from pethidine, or myself in 10yrs time with back pain (epidural) and that stalled me requesting any until suddenly it was time to push!
They say really working on your pelvic floor throughout pregnancy makes for an easier birth... I was way too lazy and didn't do any, and still managed to do it!
To wrap it up:
just take each contraction as it comes, think of it as not pain, but a natural body process.
Breathe in and out deeply with each contraction
When you feel like you just can't take it anymore, that's when you know you are almost there.

Try to get a good rest the night before, and eat well.

Oh also!! Request a catheter if you haven't peed in hours and can't do it yourself, this really made the contractions less painful for me.