if you're using square cut fabric, yes ~ you can press the seams open, but I find lining up squares is easier to do the "one row left, next row right" method...
Depending on how large your quilt will be, sometimes it works better to divide into quadrants... i.e. if you have 9 squares across, and 9 squares down total, then you'd do "interim blocks" of 3x3 ... then after those are assembled, you'd do the final joining... I have found my quilt tops are much more square that way.
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