| Primary Prompt Structure |
System + User messages. Use ### or --- delimiters to separate sections. Markdown renders natively in ChatGPT. |
XML structure tags: <context>, <instructions>, <examples>, <output>. Claude respects tag hierarchy precisely. |
Natural language with explicit grounding cues. Gemini responds well to structured bullet lists and numbered steps for multi-part tasks. |
Comma-separated descriptors in order of priority: subject → style → lighting → camera → post-processing → parameters. |
| Reasoning / Chain-of-Thought |
"Think step by step." "Reason through this before answering." Works with GPT-4o for complex logic and multi-step planning tasks. |
Claude performs extended thinking natively. Add <thinking> tags or use the API's thinking parameter for deliberate reasoning traces. |
"Think through each step" or enable Gemini's "Deep Research" mode for complex analytical queries with real-time information grounding. |
Not applicable to image models. Iterative refinement via --seed + /vary commands serves a similar debugging function. |
| Output Formatting |
Explicit: "Format as a markdown table with columns X, Y, Z." GPT-4o renders Markdown, LaTeX, and code blocks in the web UI. |
Wrap desired structure in <output_format> tags. Claude is highly faithful to formatting instructions and rarely deviates when explicitly structured. |
Specify format in the final line of your prompt. Gemini supports JSON output mode via API (response_mime_type: application/json). |
Aspect ratio: --ar 16:9. Quality: --q 2. Stylize: --s 750. Version: --v 6.1. Chaos: --chaos 20. |
| Few-Shot Examples |
Provide 2–5 user/assistant pairs in the messages array. The pattern is extremely reliable for classification and extraction tasks. |
Include examples inside <examples><example> tags. Multiple examples significantly improve output consistency on structured tasks. |
Inline examples work well. Use clear "Input:" / "Output:" labelling. Gemini 1.5 Pro handles up to 1M token context, supporting large example sets. |
Use /blend to combine reference images. Use --sref (style reference) and --cref (character reference) for few-shot visual pattern matching. |
| Multimodal / Vision |
Attach images directly to the user message. Reference image content explicitly: "In the attached image, identify and list all UI elements." |
Upload images via API or Claude.ai. Claude Sonnet excels at document parsing, table extraction, and diagram interpretation from image inputs. |
Native multimodal: text, images, video, audio, PDFs in a single prompt. Add grounding: "Using only information visible in this image, answer…" |
Image prompts: paste a URL before text descriptors, or use /describe to reverse-engineer a prompt from any uploaded image. |
| Negative Constraints |
"Do NOT include…", "Avoid…", "Do not use…" placed at the END of the prompt carries more weight than placement at the start. |
Claude follows negative instructions reliably. Use <constraints> tags for grouped prohibitions in complex system prompts. |
"Do not mention…", "Exclude…". For grounding tasks: "Do not use information outside the provided document." Gemini respects boundary instructions. |
Negative prompt: --no blur, watermark, text, cropped, low quality, jpeg artifacts, ugly, deformed. Essential for image quality control. |
| Persona / Role Setting |
System message: "You are [persona]…" Most effective when placed first in the system prompt. Persist across conversation turns. |
System prompt with role inside <role> tags, or Claude.ai's "Custom Instructions". Role adherence is very high in Claude Sonnet. |
Gemini supports system instructions via API. Web UI: start message with "Act as…". Gemini Gems allow persistent custom personas. |
Style persona via artist references: "in the style of Moebius", "reminiscent of Syd Mead", "painted by James Gurney". Weight with ::2. |