Although there may seem to be many steps to my process, please don't let it alarm you. Once you understand what to do, you will go through the steps quite fast. In addition, once a specific size is set up, you don't need to repeat the steps, you simply choose the size that you previously set up.
Note that "suggested custom page sizes" are included in every Inklingo shape collection for every layout, so you don't have to figure it out for yourself. Custom page size makes efficient use of the fabric AND the illustrations make it easy to see how much fabric you will need for any number of shapes. My information here is just to illustrate how you would go about making a variety of custom sizes. Many times I am using scraps of fabric in odd shapes, so I personally use many custom sizes.

Click the little "printer" symbol in the top left side of the screen to go to the next screen.
Click the "Read More" button below to see the remaining instructions.