I found a book called “Interlocking Crochet Patterns”, by Tanis Galik. Eighty patterns! Joy-joy!
This is called zigzag.
Here is the reverse.
This technique is called corner to corner, or c2c. It is worked diagonally. It was fun to work up.
Here’s the closeup.
This is called interlocking crochet. This pattern is Castle. I got this on u-tube. The two colors of yarn are not crocheted into each other, just around each other, until the very last row around the edge. I love this!
This is the reverse side. I need to find more of this!