While some of that will “quilt out”, in general the flatter the blocks the more smooth and polished the quilt will be. While careful cutting and piecing are key to producing flat blocks, the following three pro tips will ensure that all of your blocks are as flat as possible.
All three tips have to do with pressing. For starters, while good pressing is vitally important, pressing the seams open instead of to one side will reduce bulk and produce flatter blocks.
If you prefer to press to the side, press those seams open that will produce bulky spots.
There are other benefits to pressing seams open, as well, which are covered in the following article originally provided by Craftsy.
If you prefer nesting seams that are pressed to the side, another way to reduce bulk is to “pop” the seams in the center where several come together.
Carrie Nelson explains why and how in the following video. Not only will you have flatter blocks using her technique, but they’ll nest perfectly when it’s time to sew blocks together.
Finally, flatten the entire block during the final pressing using a great tip from Generations Quilt Patterns. It’s simple, easy and produces wonderful results.
Image Source: The photo at the top of the page is from Bee in My Bonnet. See more of this block with the seams pressed open here.