I took my swatches, knowing that the two swatches equalled one complete ball of yarn. I held the swatches up to a dress that Chickee currently wears and used it to guess-timate how many balls of yarn will be needed for the dress. (I have already used almost 2 on swatching).
I started "the Math". There will be more math after I decide how much "ease" the dress will need and what size to make it guessing how much Chickee will grow. Ease is the amount of space that is between the body and the garment. Measure your chest, for example (with just a bra on). Then take out your favorite shirt, lay it flat, and measure the chest. It will likely be 4-6" bigger than your actual chest measurement, depending on how "close" you prefer your clothes to fit. How many inches you add to your 'actual' measurement to make the 'finished' measurement of the garment, is a design decision. All the minute decisions that a designer makes add up to why one dress is different from another, and another, and another, and is what makes them original. The more unique decisions the designer makes, the more original it will be. Any of my fellow designer readers want to chime in, I'd love to hear from you!