Read your follow-up messages the way a stranger would
The messages you write for clients start to sound normal to you after you've sent versions of them many times over. That familiarity is exactly what makes it hard to spot when a message has gotten stiff, confusing, or a little too automatic-sounding to the person reading it. I catch this in my own messages more often than I would like, which is exactly why I force myself through this kind of read regularly.
Every so often, sit down and read your follow-up messages as if you'd never seen them before, as if you were the person receiving them cold. You'll notice things you'd otherwise miss — a phrase that sounds robotic, a step that isn't actually explained, a tone that's colder than you intended it to be.
This kind of review doesn't need to happen constantly, but it should happen on a regular basis. Messages drift over time as you tweak them here and there, and a fresh read catches what small edits miss.
Try this today: pick one follow-up message you send often and read it out loud as if you were hearing it for the first time as the client.