If you wake up, take a shower, use shampoo, then conditioner, dry off and get dressed, you're already a stacker. You’re naturally joining actions together and can probably identify little pockets of habit stacks throughout your day. Adding an extra action to this feels simple and can quickly become intuitive.
Illustrating the power of this approach, a study from 20132 examined dental flossing habits. It revealed that people who flossed immediately after brushing – rather than before – tended to develop stronger flossing habits overall. That’s probably because, for many of us, toothbrushing has been part of our night-time routine for as long as we can remember, so we can connect the new follow-up action – flossing – to it with ease. And the habit stuck. At an eight-month follow-up, participants who flossed after brushing consistently flossed more frequently than those who didn't adopt this habit-stacking approach.