After trying out different possibilities I ended up with this:
Some of my trial pieces have more picots in the corner. I love picots that are either a differen colour from the rest of the row or span over several rows. At the end I changed this part slightly.
I keep browsing Instagram, Pinterest and Google image search for ideas. Here's a link to Google image search "crochet overlay". That gives me many ideas of the possible techniques. In Instagram I gave my square the hashtag #overlaysquare.
I made a video tutorial of the square. This is the longest video I have published so far. It is in fact in 3 parts, otherwise it would have been half an hour long. Before editing I had an hour of clips.
This is also a test to see if a more complicated pattern will work as video tutorial. Most of my videos use simple techniques and are short.
A couple of colour variations:
