If you are on target in regards to your quilt block, you should have your Nine Patch Block pieced together. It is now time to press it. I say pressed instead of ironed because when using an iron on a quilt block it is best to try not moving in a side to side motion. You finger pressed your seams to one side as you have been piecing and now you will press on the block over the seam divide to help it lay flat.
Why do you not let your iron sway? Because seams can be stretched out of alignment, especially when working with half squares (triangles). This stretching puts stress on a seam and if quilted, that seam will wear faster. Remember that you want this quilt to be used as long as possible so give it every advantage that you can to assist in it's longevity.
Pay special attention to the four corner areas of your block to make sure seams are laying opposite to each other forming a square fan.
I'm actually going to back up a little now that I have got everyone started sewing their first block. For those not in my class, I cut the 4 1/2 inch squares out for my students but in this post I am going to back up a little and explain two ways of cutting blocks. In my humble opinion one is slightly faster than the other but not by much. When I first began I would sit in front of the TV with a TV tray and mark my squares to cut out of old clothes, sheets etc. My examples here are using a scrap of fabric I found in the remnant bin at JoAnn's fabric & craft store.
As I previously explained, you have a choice to pre-wash or not pre-wash your fabric, but I am recommending that regardless of which you choose, you iron your fabric before you start to mark and cut up your squares. Any way manufacturers fold fabric will leave at the very least a semi-centered crease or fold lines. For a larger piece of fabric it is important to be able to accurately fold fabric in half. In the picture below I took a large towel and folded it in thirds to create a makeshift ironing board on my kitchen table.
