I know there are so many threads on this but was wondering if someone could explain this to me? Read this on the Quilted Paradise Newsletter.
First, be sure to always cut your pieces as accurate as possible. Sometimes simply the width of a marking pencil is enough to cause inaccuracy. When using acrylic tools be sure to include the line in measuring. If you are cutting a two inch strip -- the previous cut edge of the fabric should include the two inch line in your strip.

I realize it should be self explanatory but I'm having a "Huh?" moment. What exactly does 'include the line" mean? My 'newbie' is showing. Thanks for your help!

I would say it means to make sure that your line is on the fabric. The line should not be to the left or right of the fabric.

Some rulers have fat lines to indicate the measurement markings and you need to be aware of how YOUR ruler is marked. On mine, for example, I make sure that the edge of the fabric is smack-dab in the very center of the fat marking line. What they are referring to is that their measurement apparently includes the marking line for precise cutting.

If you are unsure about your ruler, cut 2 or 3 scrap pieces by aligning the marking line on the edge of the fabric differently. One on the inner edge, one on the outer and one in the middle. Then measure your fabric strips to see which one comes closest to your ACTUAL size.

For me, it makes no never-mind because I don't plan my quilts to be a certain size. So for me, consistency across the blocks is more important. However, just think how a tiny difference can become a huge difference when it is repeated over all the blocks.

If your pieces vary in width by 1/8" - 1/16" due to cutting errors, and you sew 20 of them together in strips.
When you go to sew these strips together, your intersections may not line up very well. Each strip you add, will magnify this.

It gets worse when you are piecing smaller block components, say 30+ in a 15" block.

Over all it can case puckering, buckling, and be a pain in the butt trying to get the top put together nicely, and get it to lay flat :D:D:D

I have been aware for awhile that my stitcing is 1/4" but I'm still coming up with inconsistent squares. Never thought about the placement of my cutting lines. Now that I do think about it, I don't pay any attention to inside, outside, on the edge so each piece is likely different. Well, I am off to cut some scraps and see what I come up with! Thank you all sooooooo much! I love this board!

It's always the little things we take for granted that bite us in the hiney. I had to learn that one the hard way too.

There is actually one additional tip I learned a while ago. Example: If I need 4 strips that are 2.5" each, I used to cut them individually. NOW, I cut one strip at 10" and cut that in half, and then sub-cut the 5" pieces. That way I don't distribute misalignments of the ruler over each cut. Makes a difference for me.

Another cutting tip also for me at least is be consistent with the rulers you use. Stick with the same ruler for measuring and cutting for your whole project.

Chris