I recommend a simple effective method for noticing and reducing distractions in meditation. It involves counting distractions. See these resources:
A Standardized Method for Counting Distractions in Meditation: A Practical Method for Improving Focus and Mindfulness (research article)
Counting Distractions in Meditation: A Simple Method for Observing and Strengthening Attention (easy read)
Counting Distractions Across 75 Meditation Sittings: A Personal Study of Attention Over Time