Take one small tiptons jam jar. These are the little ones, about 1 1/2" high.
Take a small piece of cardboard about 2mm thick and trace around your lid
Cut out the circle
Cute out a piece of fabric which will be your pincushion fabric, about 10cm in diameter
Using tacking stitches, sew around your piece of fabric about 0.5cm from the edge
Pull the thread to give your fabric a pouch shape.
Fill the pouch with a small bundle of wadding or poly stuffing
Take your cardboard circle and put on top of the wadding
Pull the thread tight and sew a couple of stitches to secure
Now turn it over and you should have a little 'ball' of fabric.
Using a glue-gun, glue the top of the lid (this one has a bit of left over cardboard on it from a previous project, but yours will just look like the top of a tiptons lid)
Stick the 'ball' of the fabric on top of the lid and press down to ensure it is glued down firmly
To hide the join between the cushion and the jarlid, glue a piece of ribbon ( or you could cut up a piece of measuring tape as I have done on previous occasions) around the join.
You can add extra detail such as ribbon bows or buttons too.