The occiput anterior (OA) position of your baby is ideal for birth. OA means that your baby's head is down, facing your back with her back on one side of your belly. This allows her enough room to tuck her chin so that the smallest part of her head is first applied to your cervix in labor. If her head is down but in an occiput posterior (OP) position, the back of her head will put pressure on your spine during labor and may cause painful "back labor" that can be very long, exhausting and ineffective.
There are many simple ways to achieve optimal fetal positioning. Be sure to practice your posture and avoid furniture altogether, which can cause slouching. Try sitting cross-legged or in a cobbler's pose on the floor. Doing so helps to loosen you up and open your pelvis wide. Use a birth ball for sitting at your desk or while at the dinner table. Pelvic tilts should be done several times a day - watch the video below to learn the proper way to perform these. Walking at length and practicing prenatal yoga also help to move your hips and encourage your baby to move to an OA position.
Other techniques can be found at Spinning Babies, where you can also purchase a workbook to learn what position your baby is in by creating a belly map. Have fun!