What are ways to sharpen your messaging skills without having a role that builds messaging?

This is a great question! Why not take a gig? Offer your services up on a gig site or raise your hand for a stretch project at your current company. I've worked on many teams where we hosted gigs and welcomed teammates from other parts of the organization to join us in supporting a project. Partnering up on a messaging project would be a great way to get additional experience. If none of those are options, ask around and see if you have friends (or friends of friends) looking for marketing help. Start there or do the same by offering your services up on LinkedIn and in LinkedIn groups