Two tips for Shapeshifter up to level 25
First, if you’re familiar with any somewhat sophisticated graphics software that have layering (e.g. Photoshop), it’s very convenient to put the shapes each on a different layer (in black), and set the opacity of the layers to be Difference. You can then just move around each layer until you get the right final shape. It’s important that you use “Difference” as opacity, since this does the even/odd cancellation for you.
Second, if you have pieces that are a single pixel, I find it much easier to set it aside, work with the remaining pieces to get something approximately right, and then fill it in with the single-pixel pieces. When you are not given such pieces, you can also “create” your own by canceling two shapes, e.g.
When positioned appropriately will cancel the lower three pixels and leave you with a single pixel. What I do is group these two pieces together and use it like a single-pixel piece as mentioned above (of course there’s some minor limitations, but usually it’s fine). – Welkin
Try the combinations on paper
When playing Shapeshifter in levels 10 +, try the combinations on paper first, *start with the biggest shapes*, and put them into the puzzle, randomly. It doesn’t really matter where you put it, since they key shapes are actually the smaller ones. When you do it on paper, the order in which you use the shapes doesn’t really matter, since you’ll use them all by the end anyway. – bluesaphir