This is a very easy tutorial on how to crochet a Valentine heart.
You can use any size hook or yarn.
A detailed video tutorial link is included.
Tutorial includes instructions for a big heart and a small heart.
The small hear is suitable for use with key chains.
Heart crocheted with 2.75mm hook is about 4 inches for large heart.
Heart crocheted with 2.5mm hook is about 1.5 inches for small heart.