Thanks for the advice. I'll square them up. I have been pressing as I go with each step (assembly line style), but haven't given them their final block press.

Pinwheels are forgiving when squaring up. You can cut them all the same size and not loose any of the pattern. The goal of a pinwheel block is getting no cut off points in the middle. I press my seams open when making pinwheel blocks.

Square them up. It will save frustration (and cussing) later.

I put 2 squares together, then sewed diagonally.

My fabrics weren't stiff at all. Part of my problem is that the muslin kept shifting and stretching while I was tracing the template shape.

You have a good start, but I would rip out the seams that have unmatched points and redo them. You will be happier with your finished product.

Wait until you have all your blocks made, measure them all, take the smallest one and square up the rest to match that one.

They should square up nicely. The problem I had in making pinwheels is that I tend to let my seams get smaller at the end of the piece I'm sewing together. This will really mess up the pinwheel block in the center when you put it together. You might want to check and make sure your seams are consistent all the way across. Your colors are really pretty. The quilt is gonna turn out nice.

Are you using a ruler or a template? Are you using scissors or a rotary cutter? If you're using a template, I would see if I couldn't buy a ruler as soon as possible. If you're using scissors, I would also try to get a cutter as soon as possible, and of course, if you don't have a mat, you'll need one of those. Get the biggest one you can afford. Sometimes you can find these things at yard sales or thrift stores too.

For starching I use the concentrated starch, dilute 50/50 and spray it on pretty good, then I let it "soak" for at least 2 hours, then either air dry or put it in the dryer for a few minutes, then I iron. Starching will help tremendously, I believe.

Quilting is PRACTICE PRACTICE PRACTICE...

If it bothers you much, practice taking them apart and practice sewing together again. If they're cut incorrectly, practice cutting accurately again.

At least that's what I did to learn how to piece accurately.

Find your smallest block and square them all up to that size. It doesn't matter if the pattern said that they are all to be 12 1/2 and your's come out (once squared up) 11 1/2 it will just make the end result a little smaller. As long as they're square it will be okay.

p.s. I think pinwheels or any other block with diagonal seams is harder to get to come out right than if you're using square pieces.