If you go with one of the suggestions above, next time teach them the English piecing of the hexagon. I have done a flag in the small 1/2" ones but now the big 6" ones are on the market. They could just make two, sew them together and use it for a coffee mug rug. Good luck.

Hexies could be a fun project.

You could have the papers and fabrics pre-cut.
Kit them up with a needle, with enough to make one flower and let them pick their colour combo.

Have a display of different ways to use hexies ... not all just for quilts.

After you demonstrate, let them start sewing their hexies with extra kits ready for the jack rabbits!

Thanks for your suggestions... I think I'll go with travel tissue holders...and sachets...for the six people, I'll bring 3 machines...

Mug Rugs - small and easy to do by hand. -)

Twiddle and fiddle from Jennie Rayment selection made into a brooch. I've seen her do this with about 100 ladies all in one go.
I also was part of a small strawberry pin cushion .