First you cut the ribbon. If your ribbon is about 1 cm wide, it must be about 8 cm long.
Fold the ribbon in two.
sew the way you can see on the picture:)
pull tight and make a lump.
Now fold your ribbon the way you see on the picture.
Now sew the 'crossroads'.
Pull tight! and wrap your thread around the middle of your bow.
Now it should look like this.
Make a lump and cut the thread.
Now cut the ends diagonally.