So happy to take this follow up class which teaches the basic concepts of half drop construction in a raster based program like PhotoShop - the instructions worked basically the same in Affinity Photo when I used the pattern layer function. Here was my sketch:

And that got changed a lot along the way until I arrived at this final arrangement:

The basic tile that would be uploaded to Spoonflower:

And some background color variations for fun:

Thank you once again, dear Delores, for another great concept class!