This is what is on my design wall right now:
This time I'm working from a (actually I've got three...) five and a half inch jelly roll, so either cut your fabric into the desired width or use a jelly roll. Take one strip of each fabric and place them right side together. Be very picky about matching the sides to each other, to ensure a good result in your pinwheel. This fabric has been cut (from the factory) with a sawtooth pattern. Either cut the sawtooth off, or match the bottom of the Vs in the sawtooth with the clean cut side of the fabric. I'm lazy, so I'll leave the sawtooth where it is..
Now cut your strips into squares. Take a ruler and a washable fabric marker and mark the diagonal on each square, keeping the two fabrics together.
Use your quarter inch foot, and sew a seam on one side of the mark, keeping the two fabrics together.
Then sew a second seam on the other side of the mark. You can buy a special quarter inch seam ruler than helps you mark the center diagonal and the side seams. Personally I'm perfectly happy with only the center mark.
Now cut the triangles apart on the marked diagonal.
Time to set the seams with an iron, I use a small amount of steam. Some quilters do and some don't, if you are using sensitive fabrics... don't!
With the darker side turned up, flip the fabric open and set the seam turning the seam allowance towards the darker side of the square.
Now cut of the "dog ears" to get rid of some of the bulk in the center of the pinwheel.
Make the block by placing the squares in the pinwheel pattern making sure they are turned the right way. It might help to squint your eyes when looking at it.
Take the left side square and turn it over on top of the right side square.
Place them exactly on top of each other making sure the seams match up.
Sew a quarter inch seam. To speed things up sew all the squares at once, one after another. Just keep feeding the next square under your foot.
If you're wondering, I've got a Husqvarna sewing machine from the 50's. Her name is Green Greta and she is just lovely. She free hand quilts like a star.
Set the seams and iron them open just like before, seam allowance towars the dark side. You have now made half the blocks. Place one half-block on top of the other, right sides together. To make sure that the center seams of the block match up nicely take a pin and, from the wrong side on the top block, pierce the place where the seams come together.
Now pierce the bottom block where the seams come together. This ensures that the blocks are placed exactly so the seams match up.
( I could encourage you to actually put the pin where the seams come together, but why tell you to do something that, obviously, I don't...) Seriously, try to do it right.
Now place a pin on either side of the center pin, and remove the center pin.
Sew the seam, making sure you place the seam on the spot where the seams match up. Set it and iron it open.
Your first pinwheel block is done!
Good luck with you pinwheels, now I'm moving back into the sewing room to finish mine. I'll let you know how it turns out!