Knitting and crochet both require some simple tools to get started but it’s easy to collect a plethora of hobby paraphernalia.
The most basic of tools, and arguably the absolute most important, is your hands.
Without my hands, I wouldn’t have been able (or maybe “able” but “less than motivated”) to pursue my knitting hobby and career. When I teach new knitters the basic stitches or experienced knitters advanced techniques, hands are the most integral part!
I try to take regular breaks from knitting (and even typing) marathons to stretch out my wrists, fingers and palms. I definitely have hurt myself in the past by knitting too much and this usually renders me unproductive and sad for days. So, take a break knitters! Do some yoga, pour some tea, or a beer, walk the dog, take care of your most valuable tools!
What is your most coveted tool?
SillyLittleLady's Space 
I wrote about scales because I find them incredibly useful.
Thanks for the reminder to take a break. I’m taking a break from knitting to peruse the internet and do some typing. Probably not what you meant.
I think that’s great, I actually don’t have a scale yet but I know I need one!