I used to be great at resting my left needle on my thigh or a convenient throw pillow. Teaching myself to do stockings and socks was a great lesson in keeping good control of my work and I am seeing less slipped or missed stitches for it.
It's like anything else, if you really want to do it, you will find a way to make it comfortable for you. I still knit with straight needles the same way I always have, but these days I mostly knit on circs or DPNs. I'm sure you can find a way so that your hands and arms are still comfy doing your work, yet still allowing you to knit the things you want to knit. Of course, I'm one of those people who never thought "but, I've always done it this way!". I came at knitting in the round from the "I don't know anything about this method" and realizing I had much shorter needles that I was used to working with, I came up with a way of knitting that complimented the way I like to hold my needles and hands and let me keep control of the work. Of course, with that said, I knit combined so I don't have all of the jostling with my stitches that normal knitters have. I just get all the fun when I have to graft or do decreases.