Here's a little quilt I put together--
It's called Jelly Jive by Pieced Tree Patterns. It is made from a "Jelly Roll", which is a pack of factory-cut strips that are 2 1/2" x 42", composed of the fabrics of a design group. In this case, it is Pure by Sweetwater for Moda. I alternated directions in sewing my long seams to try to minimize the problem of distortion, but that still didn't prevent me from ending up with a parallelogram instead of a rectangle! In order to get this back to somewhat near normal, I had to get down on my hands and knees.
Using my big square ruler, water spray bottle and pins, I staked it out on the carpet. I used the big square to help me make sure my seams were running straight and the corners would be square. I pinned it out as close to true as I could and sprayed the whole thing with water. After drying, I did some more adjustments andsprayed again, and came out with a much better result.
I used these little pins by Bohin, they worked well, but you might have others that you like.
Here's another example of a similar problem, this time it was a print that was a little skewed, but I wanted it straight for my purposes. I cut on the lines of the printed squares, then pinned it to the floor.
This time I had my laser level and square handy, so I made use of that. I put it at a corner and used the projected laser lines to establish where my fabric should be positioned. You can faintly see the little red line on the edge of the fabric and the spot on the black cabinet in the background where the line stopped. This little tool projects 2 lines at right angles, so I could do one corner and then move around to the other corners and adjust as needed. Spray with water, let dry, and voila! No more torqued corners! My tool comes from Stanley, I am sure there are other brands available.
In between all my squaring and shaping up, I have quilted this for a customer--
Not only do I love the colors and design of her blocks, but she supplied a dark brown plush fabric for the backing, which shows the quilting lines as very 3-dimensional and sculpted. She wanted a leafy vine spreading all over the quilt, so I had fun with that. The quilt pattern is Circle Dance, the same as I used for the quilt in the picture at the top of this page. No wonder I like it!