Here's a nice article that I came across on the internet:

Question: I really don't want to have an episiotomy when I deliver my baby. Is there anything I can do in preparation for labor that will help me avoid one?

Answer: Starting around the 34th week of your pregnancy, you could try massaging the perineum (the area around your vagina). Daily perineum massage may increase the stretching ability of the area, leading to less need for episiotomy and fewer natural tears.

*With clean hands and trimmed nails, try this technique yourself, or have your partner do it for you. If you do it yourself, have a large mirror handy as well, to help familiarize yourself with your perineal area:

* Sit in a warm comfortable area, spreading your legs apart in a semi-reclined position.
Using Vitamin E oil (from punctured Vitamin E capsules) or pure vegetable oil, put a small amount on your fingers and thumbs and around your perineum.

*Place your thumbs about 1 inch (or just past your first knuckle) inside your vagina and spread your legs. Press down toward the rectum and toward the sides at the same time. Gently and firmly continue stretching until you feel a slight burn or tingling.

*Hold this stretch for about 2 minutes, or until the tingling fade.

*Now slowly and gently massage the lower part of the vaginal canal back and forth, hooking your thumbs onto the sides of the vaginal canal and gently pulling these tissues forward. This is what your baby's head will do during delivery. Continue for 3-4 minutes.

*Finally, massage the tissues between the thumb and forefinger back and forth for about a minute.

*Do be gentle, as a vigorous touch could cause bruising or swelling in these sensitive tissues. During the massage avoid pressure on the urethra (urinary opening) as this could induce irritation or infection.

*Perineum massage is not for everyone and it may not help in every case. So, the most important thing you can do is to choose a midwife or doctor who is experienced and comfortable delivering babies without cutting an episiotomy. Discuss with your doctor what your expectations and choices are in advance so that when the time comes they can follow your wishes.

sheelpa replied. No amount of massaging can help, believe me i was doing massage according to health books and i eneded up tearing and having 20 stitches, this is because my baby cam very quickly...best is to be calm and relaxed about everything. I recovered really well with alot of supoort from husband and family. When u deliver try not to be on your back lying down, i was told that if you sqwat and deliver chances of tearing are very little.