Just learned how to knit two at a time! I have second sock (and mitten) syndrome really, really bad so this is a lifesaver!
Just started some mitts, here's the pattern: https://www.ravelry.com/patterns/library/doppelbock-mitts
It's not that bad if you have a nice cable without memory (I use chiagoo). It takes a bit of practice but once you get the hang of it ...it's great. I've been obsessed with socks and mittens lately. This technique makes perfectly matched pairs with less row counting and tension differences.