To stay away from the first think, in other words to learn to steer clear of obsessive, negative, and other unhelpful thinking:
1. Complete Steps One through Nine (particularly forgiving everyone for everything, disclosing all secrets in Step Five, and completing every single amend for everything one has ever done to harm others)
2. Take Step Eleven each morning (page 86 et seq. of the Big Book)
3. Practise Step Ten during the day (pages 85 to 86 of the Big Book)
4. Take Step Twelve daily: fill one's life with sponsoring others, service, and generally being useful and constructive
5. Take Step Eleven each evening (page 86 of the Big Book)
6. Pray constantly, particularly poetic, imaginative prayers (e.g. psalms) that can be memorised and repeated on loop to block out unhelpful thinking, and establish a mental place of safety
7. Nap a lot and turn off not just oneself but one's devices
8. Mind control: one is not responsible for the thoughts that come into one's head, but one is responsible for how long one thinks them
9. Letting go: whenever obsessive thoughts recur, mentally encapsulate the subject matter in a bubble (or whatever else takes your fancy) and visualise it floating up to heaven to be taken care of by God: keep doing this till it's gone
10. Hang out with God: talk, listen, imagine, ask God to show you a world you can retreat into with Him, and you will be shown
11. Contact with reality: come back into the body, the senses, what one can hear and see and feel; engage with nature, with playing music or singing, with animals, with children, with older people, create something physical, do something practical, exercise, in fact do anything that takes you out of your head into the world
12. Answer the phone: ask God for opportunities to be useful and take up those opportunities to connect to other human beings