As a side note, I used fabric remnants, which is why I have more than the 3 fabrics recommended in the materials list.
The final quilt measures 43.5" x 37", which is a great size for a baby blanket.
Large sheet of paper (or smaller sheets taped together)
Compass or 30/60 degree triangle
44" of three different flannel fabrics measuring 44" wide
Basting spray or large safety pins
5 yards of 1/4" double fold bias tape
To start with, you need to make a template. Below is a diagram of the size of template I used. I did a 1/2" seam allowance. There are two ways of creating a template. The easiest method is perhaps through the use of a compass as in this tutorial by Dawn Chorus Studio. From the Blue Chair has a process for creating hexagons without a template through the use of 60 degree angles, however, I would just use this method to create the template so you only have to measure things out once.
Now, you will need to sew your individual "sandwiches" together so the batting doesn't shift when you wash the quilt. (Refer to Rag Quilt Instructions if you aren't sure what I'm talking about) Rather than drawing lines to sew over (which is quite a task on flannel) I ironed folds onto the front hexagon piece. Then, I used basting spray to keep everything together and a walking foot to sew.
Below are some close ups of the quilt.