Hey! I'm trying to be efficient in the sense that the tileset consists of "per color" tiles, and I'm following a self-imposed "rule" that each tile needs to be painted manually, so I'm trying to strike a balance between available shapes, the overall size of the tileset (as each different shape is actually 16 tiles) and the overall functionality and ease of use (as it's already quite big :D ). In fact, I'm not sure if I'll keep the four "corner square" tiles in the final version or just have one, in order to fit more varied shapes- in the editor I'm using to arrange the tiles (Tiled), I make use of offset layers to position the tiles properly.

That being said, there's easy ways to modify the tileset and create variations of tiles you need- just make a copy of the entire tile row and shift it as necessary :)
I'd also advise against flipping or rotating the tiles just because the light direction on the impasto would be wrong on transformed tiles!

Also, thank you very much for your support, hope you'll have fun working with these tiles :)