# Learn Claude — Part 3: Prompting, From Basics to Advanced Techniques

Prompting is the highest-leverage skill in this entire series. We'll build it in three levels — start where you are.

## Level 1: The foundation formula

Every solid prompt covers four things:

> **Role + Task + Context + Format**

❌ "Write a blog post about fitness."

✅ "You're a fitness coach who writes for busy professionals *(role)*. Write a blog post about 10-minute morning workouts *(task)*. Audience: office workers with no equipment, mostly beginners *(context)*. 600 words, friendly tone, numbered exercise list *(format)*."

Specificity isn't decoration — every constraint eliminates thousands of wrong answers. If you learn nothing else, learn this formula. Now let's go further.

## Level 2: Intermediate techniques

### Few-shot prompting: show, don't describe

The single biggest upgrade from Level 1. Instead of *describing* the style you want, **show 1–3 examples**:

```plaintext
Rewrite product names in our brand voice. Examples:

"Steel water bottle 750ml" → "The Everyday Bottle — built for your whole day"
"Wireless mouse M2" → "The Quiet Click — work without the noise"

Now rewrite: "Ergonomic office chair X200"
```

Claude is exceptional at pattern-matching. Two good examples routinely outperform two paragraphs of instructions.

### Structure with delimiters

When prompts mix instructions with data (a document, an email, code), separate them clearly. Claude is specifically trained to respect **XML-style tags**:

```plaintext
Summarize the customer complaint below in 3 bullets,
then classify severity as low/medium/high.

<complaint>
[paste the full text here]
</complaint>
```

Now "summarize" can never bleed into the complaint text, and long inputs stay unambiguous. This habit matters more the bigger your inputs get.

### Positive instructions beat negative ones

"Don't be formal" forces Claude to guess what you *do* want. "Write like you're texting a smart friend" nails it. Say what to do, not only what to avoid.

### Constrain the output shape

"Respond as a markdown table with columns X, Y, Z", "exactly 5 options, one line each", "return only valid JSON, no explanation". If you'll reuse the output somewhere (a spreadsheet, code, your blog), specify the shape and skip the cleanup.

## Level 3: Advanced techniques

### Make Claude think before answering

For analysis, evaluation, or anything with a judgment call:

> "Before giving your recommendation, first reason through the pros and cons of each option step by step. Then give your final answer with a confidence level."

Forcing visible intermediate reasoning measurably improves final answers — and lets you audit *where* the reasoning went wrong when it does. (For truly hard problems, combine this with the extended-thinking toggle from Part 2.)

### Prompt the reversal

Ask Claude to argue against itself: *"Now make the strongest case against your own recommendation."* This is the fastest hallucination- and blind-spot-check that exists, and professionals use it constantly for decisions that matter.

### Meta-prompting: recursion that actually works

Claude is excellent at improving prompts — including yours:

> "I want Claude to generate weekly LinkedIn posts from my rough notes. Write the ideal reusable prompt for this. Ask me clarifying questions first."

Answer its questions, get a polished prompt, save it as a template. You've just automated your own prompt engineering.

### Build a prompt library

The final professional habit: **stop rewriting prompts you've already perfected.** Keep a note file (or, better, Project instructions — Part 6) of your proven templates: the report summarizer, the code reviewer, the email drafter. Over months, this library becomes a genuine productivity asset.

## Debugging a bad answer: a checklist

When output disappoints, check in order:

1.  **Ambiguity** — could my request mean two things? (Most common cause.)
    
2.  **Missing context** — does Claude know what I know?
    
3.  **No example** — would one sample fix the style?
    
4.  **Contaminated conversation** — is an earlier wrong turn still in context? → *edit* the message (Part 2), don't pile on corrections
    
5.  **Wrong model / thinking off** — hard problem on a fast setting?
    

## Exercise

Take a task you do weekly. Write a Level 1 prompt, then upgrade it with one example and XML structure, then run the meta-prompting technique on it. Compare all three outputs — and save the winner to your new prompt library.

## Next up

**Part 4:** feeding Claude real material — documents, images, spreadsheets — and running genuine data analysis with executed code.