Have a bunch of regular ties, want bow ties but don't want to buy em, well you came to the right place. This will not ruin your ties. You do not need to cut anything, and with enough training this can be done within two minutes.
Step 1: Pick Your Favorite
First grab the tie you would like to convert(not permanent).
Step 2: The Finger Fold
Place your middle finger at the apex of the fat end(seam side up) under the tie, with your ring and index finger above the tie. This is where you will gently fold the two obtuse sides of the fat end of the tie (in) towards the seamless side.
Step 3: The Final Trick
Now fold the entire fat end toward the seamless side slipping it in the stitched loop, and pull it through with your free hand.
Step 4: Initial Fold
This will determine how wide your tie is so a good "rule of thumb" in this case will be "rule of hand". I personally like to have the tie as wide as my four fingers with a little wiggle room.
Step 5: The Extra Flaps
You want this to look as close to a bow tie as possible, in order to give it those two extra back flaps you need to fold it two more times. To do this simply put your hand over the fold you already made and fold over your hand, repeat this process twice for two flaps.
Step 6: The Actual Knot
Now fold the skinny end closest to the folded fat end on the seam to half the width. While holding the pre-folded fat end horizontally in place wrap the halved skinny end around vertically(all the way around to where you started), then slip the skinny end through where you started
Step 7: The Actual Look
Pull the skinny end up while holding the folds and knot down to tighten the knot and give the folds a true bow tie look
Step 8: The Loop
Well you gotta put this around your neck some how. So the loop is next, it's very easy. Just grab that loose skinny end again and push it through the knot at the same place you pushed it through to make the knot. At this point tighten the knot again to keep it from slipping out.
Step 9: The Final Product
Flip up your collar and put the tie around your neck tighten your knot more to make sure the loop stays in place. Pull the little bit of the skinny end until the tie is at the desired tightness(if there is a lot of length of the loose end don't worry wrap it around your neck and tuck it under the loop. After all this flip your collar back down and the conversion is complete.