It's Important to Press as You GoYour piecing accuracy will improve immediately when you take a bit of time to press your quilt blocks as you make them. Pressing is an extra step, but you'll love the payoff in time saved when your quilt blocks fit together exactly as they should when it's time to join them together.
Pressing seam allowances as you work helps eliminate little widths of fabric that become "lost" in seams, creating distortions and making blocks smaller than they should be.
Let's look at an example...
Your quilt block contains a row of pieced units, and in that row there are a total of ten seams. What if a pencil-line width of fabric is caught up in each seam allowance simply because you didn't press? It doesn't sound like much, but multiply that line by 10 and it becomes the difference between stitching an accurate quilt block or a block that won't match up to its neighbors.
You might argue that, if all seams are smaller by the same amount, what difference does it make? Maybe none if you're constructing very simple blocks and sewing identical blocks side by side, but the shortage will definitely cause problems in quilts where different types of blocks are sewn together, because each block will be off by a different amount.
You've perfected your quarter-inch seam allowance -- don't let inadequate pressing destroy your work. Get into the habit of pressing each unit as soon as it's assembled and you'll see an immediate improvement in your quilts.