Creating a Child Theme

You’ve probably tried to customize your WordPress theme in some way. You really liked how it looked in the WordPress theme directory or other directory where you grabbed it. But you need to change some things. Some of the colors need to be changed in order to match your branding. Or maybe you want to change how the single.php is laid out. And if you change any of the files, well, those are going to be erased. So what do you do?