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Basics · All levels · May 2026

The five most common mistakes with AI — and how to avoid them


"I've tried it — it doesn't work for us."

That sentence is common. Almost always, it's not because AI is bad for their specific use case. It's because they have made one of five identifiable mistakes. And once you know what those mistakes are, they are easy to fix.


Mistake 1: You treat AI as an encyclopedia

The most common and dangerous mistake. You ask AI about a specific law paragraph, a statistic quote, a company registration number, a historical date — and copy the answer directly.

The problem is that AI hallucinates. Not sometimes — regularly. It generates answers that sound completely credible but can be completely wrong. A model that doesn't know the answer doesn't make up that it doesn't know — it gives you an answer that sounds right.

It is a fundamental part of how these models work, not a bug that will be fixed in the next version. The purpose is to generate the most likely next word — not to search a database of verified facts.

The solution:

  • Always verify specific facts (numbers, dates, names, laws) against the primary source.
  • Use AI for what it's good at: phrasing, structure, and analyzing text you provide it.
  • Ask the model: "How confident are you about this?" — a good model will flag its uncertainty.
  • Use Claude or Perplexity for factual questions — they include source references you can check.

Mistake 2: Your prompts are too short and vague

"Write an email to a customer."

That prompt produces an email. It is technically a correct answer. But it is an email that fits everyone and therefore no one — without a specific tone, without the right context, without the detail that makes it relevant.

AI is not telepathic. It fills in the gaps with its own assumptions about what is average and generic. If you want something specific, you must specify it.

Compare these two prompts:

❌ Weak: "Write an email to a customer."

✅ Strong: "Write a follow-up email to a customer who
received a quote for 45,000 SEK for web design 10 days
ago and hasn't replied. The customer is the CEO of a
real estate company in Gothenburg. We previously built
the website for their competitor. Tone: friendly but
professional, no sales tactics. Max 120 words. End
with an open question, not 'let me know'."

The strong prompt gives a specific, usable result. The weak prompt gives you something to start over from.

Rule of thumb: A good prompt takes at least 2 minutes to write. If it took less than 30 seconds — add more context.


Mistake 3: You are choosing the wrong model for the task

Not all AI models are equal — and even the same model doesn't perform equally well on all tasks. Using GPT-4o mini for a complex legal document is like using a pocket calculator to calculate pi — technically possible, practically the wrong tool.

Task Best suited Why
Complex analysis, law, medicine Claude Opus / GPT-4o Strong reasoning skills, more accurate
Fast text generation, email Claude Haiku / GPT-4o mini Faster, cheaper, sufficient for simple tasks
Code Claude Sonnet / GitHub Copilot Trained on large amounts of code
Image + text GPT-4o / Claude Sonnet Multimodal models understand images
Search with sources Perplexity / Claude with search Connected to the internet, cites sources
Image generation Midjourney / DALL-E 3 / Flux Text models do not generate images

The most common version of this mistake is using a free model for tasks that require a paid model — and concluding that "AI can't do it" when in reality, it's just a case of using the wrong tool.


Mistake 4: You accept the first answer

AI is a collaboration tool, not an automaton. The first response is always a draft — not a finished deliverable.

Those who get exceptional results from AI models iterate consistently. They ask for three variations. They ask the model to explain its reasoning. They say "this was good, but remove X and make Y more prominent." They treat the interaction as a conversation with a skilled colleague, not as a search query.

A concrete iteration loop that works:

Step 1: Run your original prompt. Read the response.

Step 2: Identify what is good and what is missing.

Step 3: "This was good as a starting point.
  What I want to keep: [X].
  What I want to change: [Y] — instead, I want [Z].
  What is completely missing: [W].
  Rewrite with these adjustments."

Step 4: Repeat 2–3 times until you are satisfied.

Step 5: Make the final fine-tuning adjustments manually —
it takes 5 minutes and is the only way to ensure
that it actually sounds like you.

The entire process takes 15–20 minutes for a complex document. Writing it from scratch would have taken 60–90 minutes.


Mistake 5: You expect AI to replace your knowledge

The final and most subtle mistake.

AI is not an expert in your business. It has never met your customer. It doesn't know what your industry actually entails — in the specific, nuanced way that 10 years in the field provides. It can simulate an expert, but it is not one.

The best thing AI can do is help you communicate, structure, and scale your expertise. Not replace it.

The practical mistake: you ask AI to provide a strategy for your business without giving it the context it needs — and are then disappointed when the answer is generic. Of course, it's generic. You gave it generic information.

The inverse principle: the more specific you are about your situation, your customers, your challenges, and your context, the more specific and useful the AI's output becomes.

❌ "Give me a strategy to increase my sales."

✅ "I run an accounting firm with 8 employees in Borås.
Primary target group: manufacturing companies with 20–150 employees.
Biggest problem right now: 40% of incoming inquiries
are not profitable customers (too small or wrong industry).
Average customer lifetime: 2.3 years. NPS: 61.

Help me identify the three specific points in my
current sales flow that filter out the most
on-profitable customers — and what I can concretely do
for each of them."

One last thing

All five mistakes share a common denominator: they are about treating AI as a ready-made answer system rather than a reasoning support that you collaborate with.

Change the basic mindset — and everything else changes with it.

AI is like a highly skilled, extremely fast, never-tired intellectual tool that knows a little about everything and nothing about your specific context. It is up to you to provide the context. And it is up to you to verify that what it produces is actually correct.

Do that — and you have one of the most powerful work tools that has ever existed.