Writing for a Telegram channel
A channel post lands as a notification on subscribers' phones, and the notification shows the first line. That line decides whether the post gets opened, so start with the news or the point, not a greeting.
Channels are read like a feed of updates from one source. Short posts that each say one thing are easier to follow than long ones; if you have a lot to say, split it into a few posts or put the details behind a link.
Use "share news or an announcement" for updates, "teach something" for tips and guides, and "start a discussion" if your channel has a linked discussion group.
Posting at the right time, and without noise
Telegram lets you schedule a message for later from the send button, so you can write a few posts at once and spread them out. You can also send a post silently, which delivers it without a notification sound: useful for minor updates and late-night posts.
A channel that notifies too often gets muted or left. Save sound notifications for the posts that matter.