Grading - when I first started developing my own designs and patterns, I kept coming across this term "grading" that wigged me out so much I stuck to items that did not require developing multiple sizes in one pattern. Grading is the process of developing those measurements that go in the [brackets] in patterns that make your eyes go all rolley polley when you first look at them. Whenever I knit from a pattern with multiple sizes, I go through the entire pattern first, highlighting the numbers that correspond to the size I am working up. If I don't do this, I will inevitably revert to the numbers for the smallest size halfway through the pattern. (not sure if that is just because those numbers are presented first in the list of numbers or because I still see myself as the size small I was 20 years ago).
When I decided to jump into my first sweater design, I knew I was going to have to roll up my sleeves and get serious about this grading thing. A few hours into my first attempt I had 3 pages of scratched out notes. The next day, I couldn't make hide nor hare out of those notes. So I developed a better system using excel. I worked up a template using standard measurements from the Craft Yarn Council. Most of the magazines and publishers request the use of The Craft Yarn Council standards (www.yarnstandards.com) for sizing, so I use them as my basis. There are other standards out there, including a fairly comprehensive set that can be purchased from ISO (the international organization for standards). I used these measurements to make up a series of templates in excel - one each for women, men, children, girls, boys.
I then figure out the key measurements for my design, figure out the amount of ease I want in the garment, and set to work converting measurements to stitches, based on my gauge. And then reworking, also factoring in any stitch pattern constraints, etc. It's the hardest part of publishing a pattern for me, but the template at least keeps me organized. And don't forget that the measurements in your pattern need to be provided in both English and metric - the beauty of the Internet is that your pattern will be available all over the globe, so international users need to be accommodated. I'll share my spreadsheet for this sweater when I have everything worked out.
There are a couple of great tutorials on Knitty that really helped me when I was getting started. A reminder - everyone who follows on twitter or likes the Verdigris Knits facebook page will receive the pattern for this sweater.