Shorts! I made shorts from Simplicity 2654 and they fit without my having to go back and add anything at all. They fit better in the muslin than in the twill, but I'm not going to quibble. I made pants from a commercial pattern. They fit. The world as we know it has ceased to exist.
I'd show you they fit, but my photographer got a picture of her toes, the window, my knees and many other things instead of the shorts. You'll have to take my word for it. Imagine a small round person in shorts. There.
I chose S2654 because at some point in my misspent youth, I had a pair of high-waisted bell bottoms and loved them.
My goal was to make a pair of loose shorts for gardening. The high waist was the first thing to go. Inseam pockets? Who needs them in a muslin! I tried them on. They slid nicely up. I put in a zipper. They still worked. I slapped on a pair of pockets and they became phenomenal -- lightweight loose shorts that were perfect for the 99 degree weather. So I cut them out in tan twill and instantly made errors.
I managed to sew in a fold of 3 inches. The shorts zipped but pulled. I took off the pocket and repinned it while wearing the shorts. Much better. The pattern calls for a folded cuff, and the twill seems to demand that extra weight, but the muslin version behaves nicely. I'll make them again in lightweight denim and make them a little smaller. Oh, I love that word. SMALLER. Possibly narrower in the leg as well.
The secret to my success: I began with a pattern that was too big. When I started sewing many decades ago, patterns did not come in my size. I bought the smallest they had and kept taking it in until it fit. I didn't do any sewing other than mending for years. When I started again, patterns were available in the sizes I used to be. I bought patterns according to my measurements and couldn't make them work. I could make anything for anybody, but could not sew pants for myself.
This time I enlarged the pattern before I started, then basted it, and kept basting until it fit. I like this method much better than cutting in pieces here and there and adjusting the rest of the pattern endlessly.