I’m following the pattern from a Dutch magazine called Lace Collectie from Simply breien.
According to the pattern you need 3 skeins, but 2 is enough.
I modified/changed a few things.
Second round of the square I start with one chain instead of three.
At the end of round three of the triangle I made a treble crochet instead of a double crochet and I left out the two chains.
At the beginning of round six I did five chains.

I blocked the squares and triangles. Then I crochet them together (3 mm hook) with the completely flat “zipper” method.

And then I crochet the border, also with 3 mm hook.

When I was ready to start the border. I looked at the original picture up close and then I saw that every square and triangle had an extra round of sc. They did not mention this in the pattern.