Here are some tools I often use and recommend. Please know that these are only one version of each skill and you may find other versions that suit you better. 

Progressive Muscle Relaxation 1

Progressive Muscle Relaxation 2

Mindfulness of the Breath — here is a good place to start learning about mindfulness (pdf here - link is sometimes problematic)

Grounding Techniques

Sleep Hygiene 1

Sleep Hygiene 2

One topic I get asked a lot about is adolescent screen time. In 2023, the APA (American Psychological Association) came out with some recommendations based on their review of research. Here is a link to a 2022 NIMH review of studies about social media use and mental health.