Just as Ready-To-Wear usually doesn't fit me perfectly "off-the-rack", sewing patterns also don't fit perfectly "out of the envelope”. This is true for most of us. I alter most patterns that I use, at least a bit, to get a custom fit. And getting a custom fit is one reason I like to sew clothes for myself!
Most modern commercial sewing patterns come in multiple sizes, which does give you a little leeway in choosing your size. It’s easy to grade from one size to another within the pattern, which can be helpful in adjusting the sizing, especially if you fall into a different size on top than the bottom. It is a quick-fix method of grading, but not altering a pattern. You may find that you will still need to alter to fit your specific shape.
This particular top pattern design is from a pattern company (Style Arc) that makes only single size patterns. It's a bit of a throw back to earlier days when single sizing was standard for all commercial sewing patterns, but I find that the pattern drafting is so well done that I don't mind not having the extra sizes available to me. They fit me “out of the envelope” better than most. However, this pattern seemed to run a little big. The brown version of this top is the first version I made of the Patsy top design, in a silky knit with no alterations at all. My usual size 8. A nice top (and even wearable) but it was too big. All over. Too long, too wide, too loose, too droopy. But I really like the design and wanted to make it work.
Fortunately the company is kind enough to send you their grading specs when you order a pattern from them. I knew that simply sizing down would solve most every issue, so I put on my sewing geek hat and got to work.
I used the “cut and spread” method of grading for this top, and 2 great reference articles explaining that process can be found from Threads magazine, here and here. I graded the length down only above the bustline (and the sleeve as indicated) as I usually lengthen in the waist area of the body of a pattern anyway. The width was graded down one full size. The purple top is the result of that process. So much better! I see myself making many versions of this design; a sleeveless one for summer will be next.