I learned how to make bow ties when I figured out that they can be made cheaply with very simple materials. Here is a list of things that you will need to make your own bow ties:

A piece of fabric (100% cotton is best)
A Fat Quarter will be enough, 18'' by 20''

A size template for dimensions and measurements
This will save you time and ensure your bow ties are the right size, since it is hard to judge size on the fly, which I learned the hard way. This one here is cut from thin particle-board backing from some old shelves. It measures 5.5cm by 11cm, but you may want to go bigger or smaller. A good way to start is to get measurements from a pre-made one, which is what I did here.

Sewing thread
I am using upholstery thread for extra strength, but any thread will do.

Large brass safety pin
I am using a brass safety pin here, but any 2-inch safety pin works. (Brass is just stronger.)

Step 1:

STEP ONE

Fold the fabric up as shown. Use your template to get the correct width.

Step 2:

STEP TWO

When you have folded your fabric up to a decent thickness, turn it over and look at the back flap of fabric. It needs to run along the center of the folded fabric. You may need to quickly cut it if it does not, or if your fabric is uneven. You need to sew this up, but only along every inch or so. Be sure you are not sewing through the front. It doesn't matter how your sewing looks, since this will be on the inside of your bow tie and won't show when you are finished.

Step 3:

STEP THREE

Notice the two small marks on my template here. That shows the outer edges of the center knot. You need to know where your center knot goes, since a lot of your sewing will end up under that center knot. The center knot marks here are 2 cm apart, and each is 4.8 cm from their respective outer edges. Fold the fabric to the exact middle of those two lines (which is the center of the template).

Step 4:

STEP FOUR

Quickly sew the corners down, but not too elaborately. Just sew them enough to keep them in place.

Step 5:

STEP FIVE

Now fold up the other side, using your template for sizing. Sew that quickly in the same manner as you did in Step Four. Remember that your original sewn edge that you did in Step Two should always be on the inside of the tie.

Step 6:

STEP SIX

This might seem tricky, but ts really not. Turn your fabric over. Double back and fold your fabric up to match with the outer edges of the previous fold. This way, the sewed-up seam is always on the inside of your tie. Sew the corners quickly here as well.

Step 7:

STEP SEVEN

Okay , now this is a bit tricky. Fold the other end up in the same manner as Step Six. This is harder, since you will probably have excess fabric that needs to be trimmed off. (You can see it in the photo in the middle of the tie on the left-hand side.) What I do is press down hard on the fabric once you've gotten the fold right so that there will be a clear crease when you unfold it. That way, you can cut that excess off easily, and then fold the tie back together.

Step 8:

STEP EIGHT

Here, you can sew up through the middle of the fabric. Put your fabric next to the template so you can see where the center knot goes, and sew it up in what I like to call "football laces." Make sure you are sewing through every fold. My way is quick, but you can sew how you want since this is all going to be under the center knot anyway. Just don't sew too much because you have more stitches to go here anyway, as you will see in the next step...

Step 9:

STEP NINE

Fold it up like this, with one crease in the middle, and sew it through the crease to cinch it up with the outer middle edges, still minding where the center knot will go. Remember, you may need to futz with it to get it symmetrical and neat. it should look like the bow shown here.

Step 10:

STEP TEN

You need a band of fabric to act as your center knot. The concept is similar to the bigger fabric, where you fold the fabric up into a strip and sew the loose back edge. It should look like the image shown. Use your template to get the width right. (The strip shown is is 2 cm wide.)

Step 11:

STEP ELEVEN

Sew one edge of this strip to the back of the bow tie as shown, with the bit you sewed facing down.

Step 12:

STEP TWELVE

Loosely sew your safety pin to the edge you just sewed to keep it in place as shown. Watch the pin part! Wrap the strip around the front and cut it to the right length (as short as you can so that the center knot will be tight, but long enough so all the sewing is still in back of the tie). Sew the edges of the strip together over the safety pin.

Step 13:

STEP THIRTEEN

The back of your tie should look like this. The safety pin method here is my favorite for attaching to shirts, since you can just pin it through the fabric where your top button is without harming the shirts at all. (I've been dong this for years, and no shirt has been damaged so far, if you were wondering.) I can attach the tie in about a minute without looking at a mirror, which is good for getting ready for work in the mornings. And when you are done, you can just unpin it and put it in your pocket. After I am done teaching classes for the day, the tie comes off!