The AI Model Playbook
You saw the tree. Here is the depth behind it. Four models, what each one is really for, and the exact prompts to run from your own desk, in the language we actually use.
Most of us reach for the same model every time and wonder why the output feels flat. The model is a tool. Picking the right one for the task is the first professional habit worth building.
Haiku 4.5
Reach for it when speed and volume matter more than depth. Haiku is fast and cheap. It is built for the small, repeatable jobs that fill a trading day: the reformatting and tidying that eats an hour before the real work starts.
- Reformatting supplier lists into one layout
- Translating a client message across languages
- Fast unit and currency conversions
- Tidying a rough note into a readable sentence
- Strategy, pricing, or negotiation prep
- Anything where a wrong nuance costs you
- Long documents that need real reasoning
Sonnet 5
Your default for real work that does not need the heavy model. Sonnet handles the bulk of a working week: drafting, replying, structuring. It is also the model to connect to your tools, so it can read your own files instead of guessing.
- Memos, client replies, follow-up emails
- First drafts of a collection or campaign story
- Spec sheets and product descriptions at volume
- Cleaning and reformatting exported data
- WhatsApp chat exports
- Google Drive and WordPress
- Your CRM and inventory sheets
- 50+ more, so it works from your real data
Opus 5
The one you bring into the room for decisions that carry weight. Opus 5 moved up a level. It now comes close to the top model on most work, at a fraction of the cost, which makes it the right default for almost every serious task. Do not ask it to draft immediately. Ask it to question you first, then build with you.
- Pricing strategy for a line or a stone
- Comparing results across several tenders
- Planning a sourcing or inventory decision
- Structuring a full marketing campaign
- Give it the goal and your constraints
- Tell it not to draft until it has asked you
- Refine in steps, not in one shot
- Keep effort on high, always
Fable 5
Save it for the small share of work that truly earns it. Fable is still the most capable model, and it costs more. Now that Opus 5 handles most deep work, that share is smaller than it was. Reach for Fable on the hardest end-to-end tasks, or when Opus stalls. Let it run a full workflow rather than a single step.
- Researching a new market end to end
- Modeling a full product launch
- Reasoning through a genuinely hard trade-off
- Work that spans many connected steps
- It costs more tokens, so use it with intent
- Opus 5 now covers most of what you need
- Escalate to Fable, do not start there
Five habits that hold across every model
- Never let it invent specs. No carat, color, clarity, or certificate it was not given. Unknowns stay in [brackets].
- Give it a role and a constraint. “You are a jeweler advising a retail buyer” beats a blank request every time.
- Ask it to question you first on anything that matters. The clarifying questions are where the value is.
- Connect your own data so it works from your files, not from guesses about the trade.
- Match the model to the task. Speed for the small jobs, depth for the decisions. That habit alone changes your output.
AI is moving fast. Stay in the loop.
Two places to stay connected, both free, both built for our trade.