HOWEVER, I have made several different modifications to make the pattern work for my tunic idea. I wear a size 12 and I used the size 16 pattern size, for a much looser fit around the hips. I added length of course, and on the first edition I added slits on the sides, which if you've ever made a kick pleat in a straight skirt, you will know that that requires providing for self facings, that fold back and get top stitched.
But the more important change is to flare out the body, from the points under the arm, about mid-bust. This keeps the fit proper around the bustline but then provides a clean sweep down the sides for ease. This eliminated the slits, which I don't miss.
First I sew the shoulders, and then fit the sleeves and baste the first on my home machine before serging, because the easing in of the sleeve cap can cause pleating which I hate to see. Then I serge the sleeve cap and then the sleeve-sides all the way to the hem. I also have placed the bottom of the sleeve even with the selvedges of the fabric, eliminating the need for a hem. This means that the sleeves are not running vertically on the fabric, but horizontally.
May I also suggest that the fabric I used, batik, is pretty great for a tunic like this because it doesn't cling around the body. I also have some linen/rayon blend which I think will make a nice Spring tunic.
All of this may sound like a lot of work, but all three are great fitting and now I have a pattern that I can make with lots of variations.
And just now on Pinterest I saw this pattern,
http://sewliberated.com/products/schoolhouse-tunic-sewing-pattern...which looks wonderful.