Queen Mum is onto something - the pictures she posted look effortless to me.
I have a funny feeling it might have something to do with overall comfort level too? What looks effortless on someone is something that looks comfortable on that person. Something that looks effortless on Angie or MaryK might not look effortless on me, because I am not used to some of those looks/outfits yet. Does that make sense?
I had the strangest experience a few months back - I'd gone up north to visit my Mom, who was ill - and although it was technically "summer" it was still kind of cold, and I was totally unprepared for the weather, having traveled with shorts, summer tops and very lightweight casual skirts. I was freezing. Ended up at a grocery store of all places, and bought some "boyfriend jeans". Well, somehow - these looked effortless and supposedly stylish on me. They were extremely comfortable, and I could do my running around and looking after my Mom without being too cold. I also picked up a casual grey blazer too, since I'd gone up there with no jacket or coat and it was still cold. Somehow this all worked?
I think it has to do with the wearer's comfort level with what he or she is wearing - if that makes sense, and of course - it also has something to do with context/occasion as well. Oddly, when I tried to come up with the updated sweater dress formula that Angie posted a few months ago, with tone-on-tone tights, and the booties...I *felt* awkward. It looked great, but I felt weird in it. And yet, I felt good in a pencil skirt and a button down shirt on some other occasion. I don't think it has to do with casual versus not-as-casual either - it's probably mostly about how the wearer feels in the outfit. I haven't worn those boyfriend jeans much since, but they were perfect for schlepping around to doctor's appts., looking after family and running around like crazy. So...to me - it's a combination of context (ie. situation) and what feels comfortable to the wearer at the time.