Instead of tacking your fabric around your hexagon pieces, just mark a line of glue from this very convenient glue pen, press the fabric over the edge, mitring the corners. 

Then you are all ready to sew the hexagons together.

The glue pen goes on blue but dries clear.  To remove the paper after you have stitched them together, just spritz the back with water and carefully peel away the fabric and pop out the paper hexagon.

The pen also comes with a refill glue stick.

Of course, you can use this glue instead of pins for regular sewing as well.