Describing what you want takes many words and still leaves room to misread. “Warm but brief, main point first” could describe a hundred different emails. Paste one email you liked and the model sees the length, the tone, the opening and the sign-off at once.
That is the Reference check: an example or a reference for the model to match. It is often the fastest fix there is, because you usually have one already: last week’s update, a reply your manager approved, a product description that sold well.
Write a product description for our new 12 oz ceramic travel mug.
Write a product description for our new 12 oz ceramic travel mug. Match the length and tone of this one for our tea tumbler, which sold well: """ Keeps tea hot for six hours and fits every car cup holder we tried. Dishwasher safe, lid included, no metal taste. 16 oz. """
The sample shows length and tone in one go, and the instruction says which of the two to copy.
Models copy closely
The catch is that models copy examples closely, sometimes too closely. Give one example and every answer tends to come back the same length, with the same opening and some of the same phrases. Two habits help:
- Say what to copy: “Match its tone and length. Do not reuse its wording.”
- Give a few varied examples instead of one. Anthropic’s guidance suggests three to five varied examples when you use them, and Google’s suggests giving them the same structure and pairing them with written instructions. The vendor guide has both.
Examples settle judgment calls
Examples do something rules struggle with: they show how to handle the cases in between. If you are sorting expenses into categories, a rule like “meals go under Meals” does not settle whether a client lunch is Meals or Sales. One example row does. Show the tricky case and your answer to it, and the model follows your call on the others like it. See show one example for the basic move.
An example of what you do not want can help too, as long as you say plainly that it is a bad example and why. The examples and counterexamples pattern shows how to pair them.
You can also give the model the start of the answer itself. Write the first line or the first table row the way you want it and ask the model to continue. That is a reference it cannot miss, and the start the answer for it pattern shows when it helps.
Label and fence the example so the model treats it as a sample to imitate, not as text to edit or summarize. “Example of the tone we want:” followed by the text in triple quotes is enough.
Your best examples are already in your sent folder. Keep a few replies and reports that went down well, and paste one in when you ask for the next.
Your turn
You do the books for a small agency and sort card spending into five budget categories each month. A meal with a client always goes under Sales, not Meals, and the model keeps getting that wrong.
Done when your prompt covers what to make, who it's for, background facts, length, format, what to avoid, what good looks like and an example, and scores 8 or more out of 10. Edit the prompt below; the score changes as you type.
A hint
Show the model one row done the way you want it, using the case it keeps getting wrong.
Show one good answer
Sort each expense below into one of our five budget categories: Travel, Meals, Software, Sales or Office. It's for our bookkeeper, who pastes the result into the monthly expense sheet. Output a table with two columns: the expense as written, then its category. Use only those five categories. The table must be ready to paste without edits. Client meals are easy to get wrong, so here is an example row. A meal with a client goes under Sales, not Meals: | Coffee with client, Feb 12, $18.40 | Sales | """ Taxi to airport, Mar 3, $41.50 Video call software, annual plan, $149.90 Lunch with client, Bistro 22, $64.00 Team pizza for late release night, $86.00 Printer toner, $62.15 Hotel, Denver trip, 2 nights, $388.00 """
It scores 9 out of 10. Yours does not need to look like it: any prompt that passes is right.
More practice
The same idea in 2 other kinds of work. Each one is scored the same way, and each is saved in this browser once it passes.
Practice 1
You run social media for a bakery. Each new loaf gets an Instagram caption, and the one for your rye loaf got more comments than anything else this year. The new loaf is an olive and rosemary sourdough, $9, sold on Saturdays only.
Done when your prompt covers what to make, who it's for, background facts, length, format, what to avoid, what good looks like and an example, and scores 8 or more out of 10. Edit the prompt below; the score changes as you type.
A hint
Paste the caption that did best, and say which parts of it the model should copy and which it should not.
Show one good answer
Write three Instagram captions for our new olive and rosemary sourdough, so I can pick one. It's $9 and sold on Saturdays only. Our followers are mostly locals who come in on weekends. Each caption under 40 words, ending with two hashtags. Give them as a numbered list. No emojis. A good caption makes someone want to come in this Saturday. Match the tone and length of our rye loaf caption, which got the most comments this year, but don't reuse its wording: """ Dark, tangy and still warm at 8am. Our rye is back for Saturdays, and it goes fast. #ryebread #saturdaybake """
It scores 8 out of 10. Yours does not need to look like it: any prompt that passes is right.
Practice 2
You lead a sales team of six and email a short report to your regional manager every Monday. Last week’s report went over well, and you want this week’s to follow it exactly so the two are easy to compare.
Done when your prompt covers what to make, who it's for, background facts, length, format, what to avoid, what good looks like and an example, and scores 8 or more out of 10. Edit the prompt below; the score changes as you type.
A hint
Paste part of last week’s report as a sample, and say what has to stay the same.
Show one good answer
Write this week's sales report email for our regional manager, who compares it with last week's every Monday. Use only the figures below. Under 100 words, with a subject line and one line per rep. A good report lets them spot in ten seconds who is ahead of target and who is behind. Match the format of last week's report, changing only the week number and the figures: """ Subject: Week 22 sales: 4 of 6 reps at or above target Team total: $243,100 against $240,000 Rep A: $45,000, ahead by $5,000 Rep B: $36,200, behind by $3,800 """ This week's figures (target per rep: $40,000): """ Rep A: $46,200 Rep B: $38,900 Rep C: $41,000 Rep D: $29,500 Rep E: $40,300 Rep F: $44,800 """
It scores 9 out of 10. Yours does not need to look like it: any prompt that passes is right.
Quick check
3 questions. Pick an answer to see whether it is right, and why.
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You label and paste one past email as an example. Unless you say otherwise, what is the model most likely to do?
Models copy examples closely, sometimes too closely. Say what to copy, such as its tone and length but not its wording, or give a few varied examples instead of one.
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You sort expenses into categories, and the model keeps filing client lunches under Meals instead of Sales. What fixes this most reliably?
Examples settle the judgment calls that rules struggle with. Show the tricky case and your answer to it, and the model follows your call on others like it.
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Which line gives the model a reference and says what to copy from it?
It points to a real sample, names the two things to copy and heads off copying word for word. “Like our best emails” shows the model nothing, and “similar” leaves it to guess which parts matter.
Remember. Show one or two examples of what you want, and say what to copy from them.