If you haven’t noticed, I have been using yarn from my stash to make each of my squares and not buying any new. As a result, I’ve been using different yarn types together where I normally never would. The most common example of this has been using worsted weight Red Heart yarn with the lighter Caron Simply Soft. But this is more of a sampler piece, so that rule is temporarily suspended. Because the weights and textures are different, I often have to change the size of the crochet hook I’m using in order to maintain the same gauge after changing yarns.
May’s first square is another extremely simple Granny, however I found a lovely variegated cotton yarn in my stash that I used to make my family dish cloths for Christmas a few years back. The color just said “May” to me and the cotton texture will definitely stand out in the finished afghan.