When we work together, we'll do a lot of talking about the importance of creating a relaxed environment for labor... and about remaining relaxed throughout. I feel that it is the most important strategy you can employ to improve both birth outcomes and your perception of the experience.
The idea is a mind-dumbingly simple one, although sometimes challenging to execute.
When a birthing mother is experiencing fear and tension resulting from her own emotional state or something created in her environment, her body can tense up. She might crank up her shoulders to her ears, screw up her face, clench her fists or even toes, start making sounds that escalate in volume, pitch or tone. She may brace herself for the pain of each contraction as she senses it starting.
But consider the goal and the mechanisms involved. Successes during the active stage of childbirth includes an opening and softening (cervical dialation) as well as productive movement of the baby (rotation, dropping, engagement with the pelvis). A mother has to allow these things to happen. Generally speaking, more she resists, the longer all of this takes and the more difficult it becomes.
With these goals in mind, clenching and tightening don't play productive roles. Resisting or bracing for contractions doesn't help. Best case scenario involves a mom deciding to relax, trust the process and allow each contraction to do its important job... to welcome the intensity, knowing that it won't go on forever and that it all ladders to an incredible result in the end.
This is one of the areas in which it is sometimes hard for a partner to be as effective as he or she wants or needs to be. Frankly - the partner may not feel relaxed, either! Having a baby can be stressful for partners and -- despite training and reading -- they may not be prepared to provide what the birthing mother needs or wants, know how to help, understand what's normal, etc.
As a doula, I encourage relaxation by creating an environment in which a mother can feel comfortable and supported. This can include setting up a space with familiar ambiance, items, music, lighting, etc. Some moms like to have music in the room, other's don't. I remind the mom to keep a loose jaw and shoulders, help her use breathing to stay on top of the experience of each contraction, apply hot/cold as needed to regulate temperature, employ visualization and vocalization strategies. We may use movement and distraction to both aid progress and pass time. We do goal setting - getting through 5 more contractions, 10 more minutes, 1 more centimeter. We talk about establishing a rhythm, and about how that rhythm might include something the mother invents on her own and can't be taught. And so much more.
There are lots of good end results that stem from the activities above... but the big one, to me, is relaxation.
(Ina May Gaskin (known as the mother of modern midwifery) talks about this a lot in her publications and travels. A nice summary can be found in this TED Talk - "Reducing Fear of Birth in US Culture" - have a listen.)