Get a perfect glued-up panel, even with imperfect tools
When ripping a glue-line joint on the tablesaw, the smallest deviation of the blade from 90° can result in unflat panels. To avoid this, I write "glueline" on the freshly ripped edges of my pieces in the same orientation they came off the saw. I put together every joint so that the writing is upside down on one glue surface and right-side up on the other. The complementary angles cancel each other out, resulting in flat panels.
—M. Everett Clark, Marble Falls, Texas