If you work on anything worthwhile, sooner or later people will care about it and will want you to send progress updates. These could be quarterly investor updates, weekly updates to your boss, emails to adjacent teams, etc. Here are tips on how to do this well.

Understand your role, and with each update add to the body of evidence that you’re a good steward in that role. If people want your updates, they’ve entrusted you with something– a successful delivery of a product or feature, investment capital, company budget, their reputation, something. Convey that you value their trust and take stewardship seriously.
Add a little randomness to the cadence. People think they want regular cadence, but they’re happier with bounded irregularity. For example, if you send project updates every Tuesday they will seem transactional and no one will read them. If instead you send updates every 2-3 weeks, your audience will look forward to them because they’ll assume you have something new to say.
Know what your next update will be and work toward it (instead of coming up with an update when it’s time to send one). This is Headline driven development for an internal audience. If you don’t have a headline you don’t have an update, and you can’t generate good headlines post-factum.
Always start with a one sentence TL;DR and a 2-4 sentence recap of the overall goals of the project. Assume your audience is smarter than you are, but is very busy and remembers nothing about your work.
People love pleasant surprises, but these don’t come along often enough by chance. Within reason, deliberately engineer pleasant surprises so you can include them in your updates.
People hate unpleasant surprises. Obviously, avoid these if possible. But if unavoidable, take two steps. First, talk to each person privately before informing the group. Second, deliver negative news in 2-3 escalating phases. For example, start by softly expressing the possibility of a problem to give people time to adjust. The next time, state the problem as fact. (But don’t do this if there is a genuine emergency or crisis.)
Acknowledge changes explicitly. If you said a the last time and b this time, and b conflicts with a, you need to explain the inconsistency. People perceive acknowledged inconsistencies as cost of doing business, but unacknowledged inconsistencies as broken promises.
Don’t insult anyone, accidentally or on purpose. I once wrote an update that said something along the lines of “our engineers don’t know anything and therefore can’t ship, we need better engineers”, and sent it to everyone including the engineers themselves. It was factually true, but crude and unnecessary. Don’t do this.
People want a steady hand at the helm. Your tone should reflect that. You want the text equivalent of pilot radio voice. (I know, I’m mixing my metaphors.)
Many people (correctly) worry they’re being personally evaluated by their updates, so they sanitize every sentence to death. Don’t do this. Make it all about the work, not about you, and leave the evaluating to others. (I visualize myself in a third-person view physically separate from the work, and pretend my character is writing the update.)
Know the top three questions your audience wants answered, and state the answers as clearly as possible.
Add a dedicated section for worries and failures. Be honest, have good plans, and don’t panic. People are drawn to conscientiousness and vulnerability but repelled from haplessness and histrionics.
The goal of updates is for your audience to know how your project is doing at any given time without having to ask you.
“Elon yells at Wall St analysts in quarterly earnings calls, why can’t I?” If you built a company with a market cap greater than the rest of its industry combined, you have my blessings to ignore these tips.
These tips don’t work if you’re incompetent.

via Slava Akhmechet