My very first quilt top ever already taught me a lot.
The first thing I learned is the metric system is more accurate as the imperial system. When sewing, a milimeter more or less can make a big difference, especially in garments. The metric system uses centimeters and milimeters. One centimeter is 10 milimeters. With the imperial system such small amounts must be kind of eyeballed.
On the image on the left you can see the difference between both systems very clearly.
And just as it is for sewing garments, it’s very important to always measure and/or cut your blocks/sections into the right size before assembling. For the top row at the right I obviously forgot this rule. So I ended up ripping the seams of the top row, measuring the small blocks and reassemble them, taking and adding bits here and there.
It turned out all the smaller blocks were about 1/8” smaller as they should be. Probably it had to do with sewing on the bias. So for the second pillow I cutted the fabric 1/4” wider.
I also found out I’d prefer to press my seams open, just like when I would do when sewing garments. This way I will get flatter seams. All these discoveries I used on the second heart quilt top.