I thought I'd try something simple first for the rough skin on the back of my arms and the back of my legs. I know that soap in the US is very drying because Americans expect lots of suds when they lather, and the sudsing agents are drying. (If your skin feels tight after washing, it got too dry.) Sell more suds, then sell more moisturizers, I suppose. I use a very small amount of moisturizing soap in the shower, not enough for suds but enough to feel the soap slide. However, I use an anti-acne soap on my back because that was the only section of my skin that didn't improve when I switched to moisturizing soap many many years ago. For the past month, I've been very conscientious about not spreading excess anti-acne soap off my back. I've trained myself to spread soap thin, so I was putting that extra soap on the back of my arms. Guess what? My arms are so much smoother now! I can't remember when my upper arms have had such smooth skin. And what a simple fix ... I was ready to look at keratosis pilaris treatments, but this is effective and takes less time!
Just (use less) soap. So simple.