When birth occurs normally and naturally, with the mother remaining upright and active, and not rushing the process, severe tearing rarely occurs.  Studies on perineal tears vs. episiotomies show that tears heal more quickly and easily than episiotomies.  A tear is relatively easy to deal with at home, and in most cases does not require a trip to the hospital.

If the tear is very small, many mothers find that if they simply stay in bed for a couple of weeks with their legs together, the tear heals on its own without any care at all, because the edges naturally come together where they are supposed to anyway.  If the tear is larger, these are the products most often mentioned to me by mothers who have used them at home:
 

Now, what's the difference between these three products?  Basically they contain the same chemicals.  They all contain cyanoacrylate.  The difference between the Krazy Glue and the other two products is that Krazy Glue is Methyl Cyanoacrylate, and the other two products are 2-Octyl Cyanoacrylate.  What's the difference?  The Methyl Cryanoacrylate (Krazy Glue) makes a stronger bond, bonds immediate and is almost impossible to remove.  If you get some on your fingers and glue your fingers together, you have to soak them in fingernail polish remover that contains acetone in order to dissolve the glue, and even then it's very difficult to get off.  It's a very strong bond.  After the DermaBond dries, it can become pretty stiff, while the Liquid Bandage is a sturdy but not so stiff bond.  While the Octyl-Cyanoacrylate products are easier on the skin, studies of Methyl Cyanoacrylate products show that the methyl is more toxic to human tissue.

However, having said this, I have talked to people who had a very strong preference for one product or the other.  I have talked to some who said they didn't like DermaBond and thought it came off too quickly, and I've talked to others who thought DermaBond was too stiff and felt like it was poking the wound.  So you have two
kind of opposite camps.  Some people report no toxicity to Superglue at all, but they are using very small amounts.  Perhaps it has to do with your body chemistry?  I don't know.  Personally, I feel that the stronger the bond, the more toxic, and the more possibility of discomfort.  So that would put them on a continuum from:

It's really impossible to predict just how it's going to react with your body chemistry, so use your intuition to help you decide what's right in your particular situation.

No matter which product you use, place the edges of the cut or tear together, and place a line of glue across the good tissue that will hold the raw edges together.  Do not put glue on the raw edges, they must be clean and able to bond back together naturally.  Clean and dry the tissues as much as possible, because although the chemicals in these products react with the moisture in the skin to cause a polymer to be formed, the directions all say to dry the tissues as much as possible.  If you can then use a hair dryer on the area for a few seconds, this will help to set the glue.  The warmth also can feel really good to those sore areas of the perineum.

Of course, for extremely deep tears you may need stitches, but that is up to you to decide.
 

Homemade Tear Repair

Get some sap from any tree. The tree sap in this formula is what seals
the wound. The tree sap is part of the tree's immune system. When the
tree is cut, the tree uses the sap to seal the wound and kill bacteria.
It is supposed to work the same when WE use it to fill cuts. If you
don't have a tree around that has been injured and has sap flowing out,
make a cut on a healthy tree yourself and collect the sap. Keep some
around for the winter time when the sap is not flowing and you cannot
collect it fresh.

Now, you can choose to mix with the sap equal parts of whatever
antiseptic herbs you have lying around: goldenseal, echinacea, tea trea
oil, garlic. If you can't get fresh tree sap, try to purchase some
myrrh gum. Whether you mix the herbs with the sap or not, you need to
dowse the cut with an antibiotic tincture made with equal parts of these
herbs before you put on the sap.

Now if the sap is hard, you must mix it with Baccardi's 151 Rum. You
will need alcohol this strong to dissolve the tree sap. It will not
dissolve unless you have 75% alcohol.

A nurse in England who worked with Dr. Schulze, an MD and master
herbalist, said this formula works better for wounds than anything she
had seen in 30 years of being an emergency room nurse in Northern
Ireland. If you tape shut the wound for 12 hours, it totally seals the
wound better than stitches and you won't need anything for infection.

Also, slippery elm bark is spoken of as a "glue." You can make a
poultice out of it by mixing slippery elm and whatever other antibiotic
herbs you want to add. Slippery elm should be at least 1/3 of your
poultice mixture. Add enough hot water to make a gummy, gluey
consistency. Besides being a glue, slippery elm draws out poisons,
soothes the skin, and reduces inflammation. Once it dries, it takes a
lot of effort to remove it. My source says that if you add a layer or
two of cotton gauze over the poultice and press it in, it will make a
cast even an orthopedic surgeon will admire.

Now, I supposed you could just make some of this sticky mixture, glop
some on the tear with the edges as close together as possible, and let
it dry.

Of course, if you don't have the other herbs, just the slippery elm and
water can be used also.