Mark a line along the edge of a washing powder or cereal box. Then from this line up to each opposite top corner.
Before cutting using a craft knife.Cut out a short length and a long length of material, I used the very scientific method of placing the edge I wanted to cover against the material and drawing round it! Always iron it first and stick on using good old craft mount.
Now for the bow attachment;
Take a piece of the same material, I didn't measure it but it was probably about 30cm by 40cm for those that need specifics - this doesn't really matter though as it can be any size you like. Iron it out.
fold inwards, like doors. Lengthways first...and iron again.
Then fold the short ends in. Iron.
Et voila...
To attach it to your folder holder use a hot glue gun or some strong glue. You could also use these bows to attach to hair clips or Alice bands if you want to use them to jazz up something a bit dull or give it a new lease of life.