This article has a great script that you can use during morning meeting to support one minute of mindful listening and one minute of mindful breathing. It also has some great tips for creating a successful practice.
This is a great getting-started resource because in minutes you can be practicing mindfulness with your students. Just pull up the free website and invite students to sit quietly and breathe, or play one of their guided meditations. I love to use the two minute guided meditation as a way to help my K-2nd grade students transition to new activity