Do you muslin something as simple as a t-shirt or pop-over blouse? I don't, generally, but I was prepping some older patterns I thrifted recently, and found that this McCalls 6091 90s suit pattern had a hidden gem: a nice boxy blouse with lots of potential.
This top's recommended fabrics are a challis or soft cotton kind of drape. I never usually try out such simple things before using my intended fabric, but this time I'm planning on cutting up an old dress and didn't want to waste the limited and very pretty fabric. So I found a scrap in my stash that was just the right size (about 1/2" waste left after cutting this out) and went ahead. And after I cut it I realized that I'd used a knit to muslin for a woven. Doh!
But I continued on since this pattern is quite literally two pieces. Plus neck facings, but I left those out on this trial make and just turned and stitched. I really just wanted to see if I'd got the sizing right.
And I did, if I'll be using a knit in future. In fact, I quite like the shape and fit of this as a simple tee, and think I might just be using up a few more little leftover bits to make myself some colourful summer tops.
As for alterations: I cut the neckline much higher than the pattern indicated, more of a boat neck style. The "U" neckline might be pretty but it is also far too low for my body as it is patterned. So even if I do use more of the original shape next time, it will be raised.
I also gave myself an extra inch on each side seam of front and back when cutting out. I graded out from just below the bustline to the hem. It was perfect. I just turned and stitched the neckline and the sleeve and bottom hem, using a long and narrow zigzag. It works fine on this busy print, you can't really see the stitches at all, and there aren't any puckers.
So someday I really do intend to make this in its proper incarnation as a woven top, but for now, I'm quite happy with this wearable muslin.
Maybe I should muslin more often!