Remember to breathe!
When I had my first baby I kept panicking and forgetting to breathe during contractions. it didn't help that she wasn't in a good position and I ended up with a forceps delivery. All was well in the end and I have a lovely healthy dd.
With my second baby I was determined that things were going to be different.
I stayed up on my feet as much as possible. When having a contraction I leaned on a chair or on the bed even against the wall. Took really deep breaths in through my nose and out through my mouth.
It was really painful if I tried to sit down so I spent some of the labour on the bed on my knees leaning forward over a pile of pillows. Made me feel a little less tired.
They brought me the birthing ball which I'd heard such good things about on mumsnet that I wanted to try but it was so painful to try and sit down on it I didn't use it. But other people have said it worked wonders for them so give it a try if you want to.
Don't go in expecting that labour will follow Your plan, every labour is different and there are no rules.
Every contraction is one less to go through before your baby arrives.
Drink lots of water.
Try gas and air if you want to. You might not like it but theres no harm in trying. I didn't like it with my first dd but with my 2nd dd I used gas and air for the last 2 hours and it was fab.
Try to stay relaxed, you can do this it's what you're designed to do bringing babies into the world.
It is hard work and it is painful, well I thought more uncomfortable than painful but maybe that was just me. But at the end of it all you'll have your lovely baby and it's all worth it in the end.
Good Luck and remember to breathe