Summary: The GitHub repository "brexhq/prompt-engineering" provides tips and tricks for working with Large Language Models (LLMs) like OpenAI's GPT-4. The guide covers topics such as the history of language models, prompts, hidden prompts, token limits, prompt hacking, and prompt engineering. It also discusses the need for prompt engineering and strategies for working with LLMs, including embedding data, using simple lists, markdown tables, JSON, freeform text, nested data, citations, programmatic consumption, and chain of thought. The guide also covers downsides of LLMs and provides additional resources for further reading. The repository is licensed under the MIT license.