If you’ve ever made a quilt you know how confusing it can be to figure out what side you should press the seams towards so, when you start sewing rows together they match and abut nicely. Here is a tip I have come up with over the years and it works for me just fine.
Generally I press my seams towards the darker fabric (so you don’t see the seam through the light fabric) but if the fabrics I’m using aren’t dark, then I tend to press my seams in whatever direction I’m feeling like it while the iron is in my hand. In order to get all my seams to abut nicely, I just make the seams abut regardless of the direction the seam was pressed in to begin with. Here is what I mean:
Here you see the seam has been pressed in to different directions. When I made the row I pressed the seam towards the right. Now that I am sewing two rows together, I am forcing the seam to flip back in the opposite direction. I put a pin at the seam intersection and sew the rows together.
To resolve the issue of having a bulky seam underneath because its going in two different directions. I grab a pair of scissors and very carefully snip right below the seam line… making sure not to snip the other seam line. Then I press again to make sure the seam is laying flat.