Gather some denim and lace scraps.  Draw a flower shape on paper and cut out.  This does NOT have to be perfect! As you can...I'm definitely NOT an artist! Trace onto the denim.  
 
Cut flower shape out.

Nice stack of flowers.....you will need 10 denim flowers and 10 lace flowers.

Fold each flower shape in half....

And in half again and pin.

Another view of the pinned petals.  Do this to 6 lace flowers and 8 denim flowers.

Make a 'sandwich' of lace-denim-lace out of the remaining flowers.  These will be the flowers' center.

Fold in half....And half again....

And fold again to end up with this.....

Now take the pile of flowers to the sewing machine and sew 5/8 inch from the pointy end.

A pile of folded and stitched flowers.  Not all are in this picture.  You will have 8 plain denim, 6 plain lace, and 2 denim & lace sandwiches.

Arrange four flowers as shown and sew onto a scrap of denim.  You can use a glue stick to hold it in place until you sew it.  

 Arrange four more denim flowers on top and stitch into place.

 Here is what you end up with at this point.

Next, take 4 plain lace flowers and tuck into place in between the two layers of denim flowers that at sewn into place.  I used a hot glue gun and glued them into place.

Take the folded flower sandwiches and glue them in the center.  Tuck the final 2 plain lace flowers in the center.

Glue a small scrap of felt onto the back along with a pin.
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Flower pins finished!

A side view....