Here is how:
Get yourself some Best Press Spray Starch...you will thank me. It runs about $8.99 but it lasts a while and plus you can add a tinsy bit of water to it so it will last longer. Get some good smelling kind like the lavender. I wasn't a huge fan of the clean linen smell - it smelled a little 'producty' once ironed, but that's just me. :) Okay, so you got your rotary mat (mine was a TRUE find at JoAnn's because it has owls all over the back and one on the front). I ♥ Owls. Okay, sorry - sidetracked...moving on...you got your pincushion with plenty-o-pins, a nice squared ruler template and a long ruler like 3 or so inches wide. I highly suggest getting one with a 'lip' on the end. I had NO clue what that was for...till I found out you can hook it to the end of your rotary mat to make the ruler line up nice and straight. Hello-genius!!
For Pinwheels, cut out a background fabric and a patterned fabric for the 'wheel' part both the same size. I just used my squared ruler so I didn't have to measure (I believe it's 8x8). Line up your background and patterned fabric together, WRONG sides together - meaning both of the front sides of the fabric are in the inside. You can pin the square together if you desire. Stitch around the entire block of the square, using a 1/4" seam allowance. When quilting, always use 1/4. It's the bomb..so remember it. :)
Once you have your square sewn all the way around, lay your ruler precisely from one corner to the other and cut.
Then do the same on the other side.
Take the bottom row, and sew your two blocks together. Match up your seams so they will be straight. Repeat with the top row. Once you have them both sewn, iron the seams again, lay them flat like the picture, then sew them together. Iron again. LOTS of ironing. :)
Once all rows are done, take your long ruler and trim any sides that are not straight so it is a perfect square. Voila! Your pinwheel is done! Isn't that so incredibly easy? And fun....once you find some fabric you love, you can whip these babies out in no time. I prefer a Sunday afternoon, with a Diet Pepsi while Robot Husband watches football and the kiddies run around. :) Enjoy!