7. One little gotcha to be aware of is that because the text is all being centered, if you have an uneven number of squares (say 2 and 3) the squares will be offset like this, which is probably not what you want:
To fix this, just make a 'blank'polyomino that you can use as a placeholder in this situation. In the examples below, I've made a blank image with a border just so you can see it, but note you're better off just making it be a transparent square.