Deb Gemmell and I worked on a series of plus size patterns that have now been published. You can see the collection here. During the process we worked on a shrug variation which wasn't included because we weren't happy with the final result. I see a lot of value in examining failures. I believe that failures offer more information for improvement than our successes do. With that in mind here are my thoughts.
There were two prototypes. I was concerned going in that the first version was using a yarn which was too heavy (worsted). I'm not 100% sure that that was the only problem, but we cut that pattern early on in the process. The garment was a long sleeved version with a wide band that was worked out circularly on the fronts, neck and lower back edges. The band turned back at the neck to create a collar which included short rows to make it longer. It had a deep trumpet cuff on the sleeve. I think we missed out on more lessons that could have been learned from this one by moving on without further serious critiquing at this point.
To create the second version we switched to a fingering weight yarn and used a looser gauge than recommended on the ball band to create a fabric with drape. We switched the band and cuff stitch pattern to a lace faggot stitch from the previous version that used this ribbed slip stitch. Unfortunately I can't find an online photo of the lace version to link to.
This one looked better on a mannikin but also failed when we moved to a model. I think the failure was in three areas. The first was a mismatch between the models body proportions and the garment proportions. The second was possibly a styling issue. The shrug was a lovely coral shade but the model was wearing a black jersey top underneath with contrasting trousers. That meant two horizontal lines crossed the body. The third possible fail was the drape of the fabric was simply too limp, the collar suffered without structure. The side of the shrug fell straight down instead of staying against the body. The very curvy body shape of the model might have been more flattered by a fabric with a stiffer hand. The success with this version was that the model loved the trumpet cuff and the much longer sleeve does break up the horizontal line on the body that short sleeved shrugs create.
My suggestions for choosing a shrug pattern to knit would therefore include picking one that has sleeves at a different level than the body of the shrug, either longer or shorter. I would also choose yarn in a similar colour to that of the garment the shrug will be worn with. A dress might be better than separates to eliminate an additional horizontal line on the torso.
If you are looking for upper arm coverage only, consider carefully where the sleeve hem is in relationship to the body of the shrug.
Styling matters.The fabric should match the underpinnings in terms of formality. Heavy or light weight knits may look odd paired with contrasting weight fabrics and low colour contrast is very important.
Take a look at this link. You will notice that each shrug is photographed with a same colour under garment. They are worn open to create two vertical lines instead of a horizontal.
This link shows a version that has some of the problems that you should consider avoiding.
I'd be very interested in hearing your thoughts. Are there any other tips you could recommend?