In order of appearance…
Mindful breathing: Take 10. Or just 5 if this is all you can mange to sit and observe your breathe. Stay present. Notice the pull to distraction and without judgement bring your attention back to your breath.
Visualising: Use this brain flaw to your advantage. Imagine a positive scenario. A beautiful beach with humming waves and gentle sun. Or a great social encounter if you’re dreading something coming up.
Thought stopping: a simple technique to stop intrusive thoughts. Imagine a big red stop sign in your head if this helps.
The shrinking thought: another visualising trick imagining your negative thought gradually getting smaller until it completely disappears.
New routines: my clients must be sick of me talking about the importance of routine and scheduling. Introduce activities that give a balanced sense of responsibility, achievement and pleasure. Affirmations, meditations, or a gratitude diary are great examples.