Some useful insight here from Angela Moore writing on the excellent Scroll blog. If you've ever needed a style guide or you have one and no one uses it, this is a really good place to start. Allow me to share a tip of my own. It sounds silly, but there is one style guide of mine that got used the most. I knew it would make a huge impact if everyone embraced it, but there was low digital maturity in the team. So I printed hard copies out and put them on everyone's desks. It worked because they could see it right there in front of them and watch each other use it as a reference document. Within a few months, they were adding new stuff to the guide themselves and gradually we all moved to the digital version, which was collectively kept up to date. Win!