When choosing a PHP project directory structure, there are a few things to consider:

1. Keep it organized: Create separate directories for different types of files, such as code, assets, and data.
2. Use a logical naming convention: Use clear and descriptive names for your directories to make it easier to find and understand their purpose.
3. Use a consistent structure: Decide on a structure that works best for your project and stick to it throughout the project to avoid confusion.
4. Keep it flexible: Your project may change and grow over time, so choose a structure that can adapt and accommodate new features and functionality.

Here is an example of a common PHP project directory structure:

project-name/
├── src/
│ ├── controller/
│ ├── model/
│ ├── view/
│ ├── config.php
│ ├── routes.php
├── public/
│ ├── css/
│ ├── js/
│ ├── img/
│ ├── index.php
├── tests/
│ ├── unit/
│ ├── integration/
├── .gitignore
├── composer.json
├── README.md

This structure separates the source code (src/), public assets (public/), and tests (tests/) into separate directories. It also includes directories for controllers (src/controller/), models (src/model/), and views (src/view/) to organize the different components of the application. The public/ directory contains the publicly accessible files, such as CSS, JavaScript, and images, as well as the entry point of the application (index.php). The tests/ directory contains the unit and integration tests for the application. Finally, the .gitignore file specifies the files and directories that should be ignored by Git, the composer.json file specifies the dependencies for the project, and the README.md file provides documentation for the project.

This is just one example of a PHP project directory structure, and there are many other ways you could organize your project. The important thing is to choose a structure that works for you and your team and helps you keep your project organized and easy to understand.