I like the Fisherman Sweater (L.L. Bean is a good source) and have one in a rust/brown color. Also plan to get one in the classic cream/ivory color. I think they come in both longer and cropped lengths and I prefer the longer one for autumn.
Since they are on the thicker side, I usually wear them without a jacket. They are so easy to throw on and look effortless. I pair them with skinny jeans, ankle boots, and of course a nice handbag. I am not into scarves so I would just wear some drop earrings with it.
If I am layering under a jacket or blazer, I tend to prefer light weight wool sweaters. Cashmere is always good, so soft against the skin and warm without being bulky.