I'll start with the hat.
Actually, I'll back up - I think I was avoiding doing a lot of piping during these few years. I am pretty sure my carpal tunnel stuff was bothering me a lot back then, and painting with food coloring or just coloring fondant and rolling it out were easier things to do, wrist-wise, than squeezing a piping bag of royal icing for a long time.
Anyway. The witch's hat was a lot of fun to make. (I say that about a lot of these, especially the ones for my sister.) It was chocolate cake, layered with chocolate frosting, and then carved into the hat shape.
I remember that when I cut out the black fondant for the hat and wrapped it around the cone-shaped cake, I had problems. Gravity was one of them. There was a lot of fondant slouching going on, and I think it ended up as a sort of patchwork of pieces that I pinched together, using a bit of water as glue. So the lovely seamless black hat I'd envisioned was dumpy and worn-looking. Ah well. So now what? How to fix it? Or maybe not fix it, but work with it and make it into the hat it seemed to want to be. (Oh really, Jayne. That's a bit much.)
So I thought, okay, apparently it is a dumpy, worn-looking patchwork hat. Maybe the witch has had it for years and it has meaning for her and she can't just get rid of it. So she fixes it up here and there when a seam bursts or the fabric wears thin, and she keeps wearing it, because it is precious to her.
Anyway. I colored some royal icing and piped on large, brightly-colored stitches where the seams were visible, and used a similar stitched look for the lettering. The bright orange band around the hat and the pink button were fondant, too. Overally, not really a difficult cake to build. And I think Meredith was happy with it.
The other cake was similar to the Power Puff Girls in technique - I had a circle of white fondant and then I painted that character on most of it and wrote the Happy Birthday Calvin part on the rest. Then I covered the rest of the cake with swirls of white icing. I'm pleased with it. So was Calvin.