You need 2 sizes of hexagon, 1 for the paper pieces and 1 for the fabric pieces, this is the size used for the paper hexagon with a seam allowance of your choice all around usually about 1/4" / 6mm
I use normal printer paper for my hexagons, not the really cheap stuff just the normal weight paper. When I print stuff instead of recycling it in the recycle bin I cut hexagons from it. I also recycle leaflets and junk mail that keeps coming through my letterbox. I have used 2"/ 5cm sized hexagons (the paper hexagon size) but you can usethe size you prefer.
2. Fold over 1 edge, I usually run my fingernail along the seam (finger press). Tack the fabric to the paper by starting in the middle of the seam do a few small stitches or knot the thread to begin with (whichever method you prefer to do!)
3. Fold over the next seam and finger press, make a stitch or 2 in the corner through all the layers of fabric and paper. Make another stitch in the middle of the seam.
4. Repeat until last fold. Fold the corner fabric to match the other sides, stitch to secure.
You need 7 hexagons to make a flower (my next hexagon how to make)