I get so much satisfaction when seams meld perfectly that I'm going to try for that every time!
One thing not mentioned so far is to try a different foot. I was getting mismatched seams every time with my original foot so I got a walking foot, but that made it harder to keep an even seam allowance. Then I tried a different 1/4" foot, and that has helped the most, both for even allowances and matched seams; it doesn't push the top fabric more than the bottom, which my first foot did, so pinned junctions now match way more often than not, whether pressed open or to one side.