Change the cue

Every habit has a trigger. The usual ones are a place (the sofa, your desk, bed), a time (after lunch, last thing at night), what you've just done (finished a meeting, got home), other people, or a feeling (bored, anxious, tired).

Next time you catch yourself mid-habit, ask: where am I, and what just happened?

Small obstacles have a big effect, because habits run on whatever is easiest. For a habit you want to break, put distance between you and the cue: log out of the app, keep the cookies on a high shelf, charge your phone in another room. For a habit you want to build, do the opposite: leave your running shoes by the door, and the book on your pillow.

A plan in the form "When X happens, I'll do Y" works far better than a general intention like "I'll read more". It ties the new behavior to a cue, so the situation reminds you, instead of you having to remember.

• When I sit on the sofa after dinner, I'll leave my phone on the kitchen counter.
• When I start worrying in bed, I'll write the worry down and leave it for the morning.
• When I close my laptop for the day, I'll go for a ten-minute walk.

Jo scrolls her phone in bed every night, often for an hour, and then can't sleep. Every morning she tells herself she'll stop tonight.