Your perfect development environment!
Does your project require servers running on Linux? Get those servers on Docker containers! Since each container is isolated and minimally configured, you should be able to manage or troubleshoot them more easily. Since you can maintain multiple versions of the same server, you can also readily setup servers depending on your project.
For example, when you're developing a WordPress theme, you can simply create containers for WordPress and MySQL as their official images are already available. WordPress image includes everything (ex. PHP, Apache web server and etc.) except MySQL. Thus you need to create a container for MySQL and link that with WordPress.