When tying a bow, your first inclination may be to follow your shoelace-tying instinct. If you do this, your bow will end up looking like a puny figure eight, not the big, puffy bow you're hoping for to decorate your chair. You will use some familiar steps from a shoe-tying bow to create the perfect chair bow, however. This technique works well for tying a chair sash on a chair for a dinner party or over a chair cover for a wedding.
Put the middle of the sash around the front of the chair and position yourself behind the chair with one end of the sash in each hand. Cross the left side of the sash over the right and put this end in your right hand. With your left hand, pick up the end of the right sash. At this point, your left hand should have the side that was originally on the right. Your right hand should be holding the the side that was originally on the left.
Take the sash in your right hand down and back up behind the sash in your left hand. This is the beginning of a knot.
Create a loop with the left-hand side of the sash. This will be one side of your bow. Making a loop is as simple as the loop made while tying your shoes. Just pull up fabric and pinch in your fingers like you would do while tying your shoes.
Now take the sash in your right hand and bring it over the "neck" of the loop (the part where your fingers are pinching the loop.) This is the trick to making a bow look nice. This is the "knot" in the middle of the bow. After bringing it over the neck, shove the sash directly behind the loop, through the new loop you created by bringing it down over the neck, and pull to the left with the fingers you were using to hold the original "neck."
Pull both sides of the bow to tighten the knot. Now you can adjust each side of the bow to make the bow larger or smaller. Getting the hang of this takes some practice, as you may find it difficult to undo your shoelace-tying instinct and have to retrain yourself each time you need to tie a bow.