I want to send a newsletter every week, and I want it to sound like me.

An issue or an essay: pick the format first

Newsletters come in two shapes, and they need different settings.

An issue is news plus a story plus one ask: a shop's Friday email, a club update, a weekly roundup of links with a line on each. Use the Email format with Email type set to Newsletter. The draft starts with a Subject line and a Preview line of up to 90 characters, then a short personal opening, 2-4 sections under their own headings and one call to action at the end. Long runs 250-600 words and Medium 120-250. The subject is aimed at under 50 characters, with a warning above 60, and the preview gets a warning past 90.

An essay is one argument or story told at length, the kind of post many Substack writers send. It needs more room than the Email format gives, so use the Blog post format: set Article type to Opinion / experience, choose Enter a word count under Length, and switch off the FAQ section and meta tags in More details. Then write the subject and subtitle yourself in your editor.

A rule of thumb for telling them apart: if you could cut the piece into three separate items and each would still make sense, it's an issue; if cutting it breaks the argument, it's an essay.

The Newsletter draft uses headings for its sections. The plain-text version drops the heading marks and keeps the section names as lines, and the HTML version keeps them as headings, so copy whichever your editor handles better.

Openings, subject lines and preview text, before and after

The first lines of an issue are where it most often sounds generated. A typical draft opening: “Hello friends, I hope this email finds you well. This week has been an exciting one here at the shop, and we have so much to share with you.” That's 140 characters, and a reader who gets through them has learned nothing. The same issue, opened with the best thing that happened: “Forty people came out in the rain on Tuesday to hear a man talk about drains for an hour, and we sold every copy of his book.”

A personal newsletter has the same problem in different clothes. Before: “In today's issue, I'll be exploring why I stopped using a to-do app.” After: “I deleted my to-do app on 2 March and haven't missed a deadline since.” The second line is the news; the first only promises it.

Subject lines follow the same rule. “Exciting News and Updates From Our Bookshop This Month” is 54 characters and could head any issue from any shop. “Forty people, one book about drains” is 35, “Signed copies, Thursday only” is 28 and “Our November reading list” is 25. With Subject line ideas on, three alternatives like these appear under the email.

The preview line is the text many inboxes show beside the subject, so don't spend it on a greeting. “Plus: we're closed on 14 November, and Amira's pick for long train rides.” is 73 characters and adds two more reasons to open.

On Substack you can let readers choose the subject for you. Its help center describes a title test for publications with at least 200 subscribers: alternative titles go to part of the list, 50% for one hour is the recommended setting, and the title with the highest open rate then goes to everyone else. The three alternative subject lines are ready-made entries for it.

Keeping your voice from issue to issue

Readers stay subscribed to a person, so voice matters more here than in almost any other email. Part of it lives in the sentences: how long they run, how you joke, the words you would never use. Part of it is the furniture readers learn to expect: the greeting, the sign-off, the names of your regular sections, the way you introduce a link. Put the furniture in the request (open with ‘Morning, all’, end with the ‘From the counter’ section, sign off as Jo and the team) and the draft keeps it.

The sentences come from a voice. Under Voices, paste 2-5 pieces you wrote yourself, at least 300 characters in all; HidenGPT notes your tone, sentence length, the words you reach for and the ones you avoid, and your formatting habits, and it keeps a few short excerpts as examples. Old issues written before you used any AI tool are the best material, followed by replies to readers. Leave out issues a tool or a co-writer drafted, or the voice copies them instead of you. Voices need a plan: Pro keeps up to 5 and Pro Max up to 20, so a shop newsletter and a personal one can each have their own.

After the draft, a light red pen pass cuts stock phrases and breaks up flat rhythm, and you see a naturalness score before and after. It's an editing score, not an AI detector.

What to cut before you press send

A last pass, in this order:

1. The throat-clearing: apologies for being away, the weather, “I hope this email finds you well”. Start at the news. 2. The recap. If the last paragraph repeats the sections in smaller words, delete it and end on the ask. 3. Every ask but one. Reply, buy, share and follow are four requests; pick the one that matters this week. The Newsletter setting is told to end on a single call to action for exactly this reason. 4. Announcing instead of telling: “exciting news”, “big update”, “dive in”. Say what happened. 5. Spam-filter bait. The format warns about wording such as “act now”, “limited time”, “100%” and strings of exclamation marks, and it's told to avoid words in all caps. 6. Links you added out of habit. Keep the ones you would click yourself. 7. Footers written by hand. Your sending tool adds the unsubscribe link and the postal address, and HidenGPT is told not to invent them.

Then send yourself a test. Substack's help center notes that a test email shows how the post will actually arrive in inboxes, which may not exactly match your site's theme, so read it in your own inbox, on your phone, before the real send.