Tychs are a form of photo sequencing where an artist makes two or more separate pieces that can stand side by side and complement each other.
The format of the pieces may be landscape or portrait, but they will usually be the same size. It is sometimes a continuous but divided image, or may be composed of separate, closely related images.
These pieces make for great home decorations because they tend to fill up a large portion of wall space and look less bare than a single image. Tychs offer a completeness that is unique to them. \
Tyches do not need to be soly diptychs, or two images that lay side by side. Tychs can be many images. Two images, however, is the most common form of tech created.
When starting out creating a tych, be sure to use complementary colors. Even if your images aren't the same, you'll want your viewer to get a sense that they belong together. Diptychs tend to use images that nod to the same theme.
The other route to go when creating a diptych is to make images that are clear opposites. This way, the viewer will not be confused by your images, and will still be able to see the relationship between both of your images.