You’ve heard about habit stacking. Attach a new habit to one you already have. Do the new thing straight after the old thing and it sticks, because the old habit already runs on autopilot.

It’s good advice. It’s also half the story, which is why people try it, get a week (at most) out of it, then stop and wonder what went wrong.

the idea, in short.

Habit stacking is one practical example of the wider idea of habit hacking. It uses an existing habit as an anchor. You brush your teeth every morning without thinking about it. Attach flossing straight after, same spot, same moment, and flossing borrows the automatic nature of brushing. No decision required. No remembering. The anchor does the work.

It’s solid habit science. You’ll find it in nearly every book on the subject, James Clear’s included. The mechanism holds up. Mostly.

why most habit stacks fall apart.

The stack often isn’t the problem. What tends to go wrong is how we design it. In the flossing example, you have a morning routine where something else usually happens on autopilot after you clean your teeth. So, you are inserting flossing into the middle of a routine That’s OK. But it needs a bit of work to effectively disrupt and rebuild your routine.

I see this constantly. Someone picks a habit that sounds good on paper, often something that worked for a stranger on a podcast, and stacks it onto a morning that’s already full. It lasts until the first disrupted day, then it’s gone, because it wasn’t built with consideration for the existing habit, how it works and what else is specifically going on for you.

A common pitfall, particularly with taking someone else’s habit, is that it’s too big. If you don’t choose a small enough habit you may struggle to maintain it. If your morning routine is anything like mine, it’s had years to settle into something efficient. Adding in flossing is small and will work. Trying to insert something that takes more than a couple of minutes can throw everything else off and create stress.

Environment is another important consideration. In fact, for some habit stacks, it’s the most important thing. A habit that needs you to find something, move something, or remember something out of sight loses the anchor’s momentum. The next step must be obvious. Most habit stacking advice skips straight past this and leaves you to work it out alone.

Again, going back to the flossing example. If your routine requires you to open the cupboard and get the floss, that could be the weak point. If you store your toothbrush in the cupboard and your floss is next to it. You’ll see it and that’s your prompt. But if your floss lives somewhere else, out of sight, that’s going to be a problem for you.

why it works when it works.

Stacking works because it removes the moment of deciding. You don’t decide to floss. You just floss, because it’s already attached to something you do without thinking. That’s how it is generally presented and it’s not wrong. But it misses the most important point. There are upfront decisions to be made and then a bit of environmental design.

First, you need to decide that you want to floss every day, determine if it’s small enough to be realistic and that it makes sense to do it after you clean your teeth. Then you need to make the floss visible at exactly the point where you will use it, e.g. next to where your toothbrush lives. These are upfront decisions that need to be made once. This is what James Clear means when he says, ‘make it easy’.

Now, everything is in place, so you don’t need to talk yourself into it. There’s nothing to talk yourself into. It’s already moving before you’ve had the chance to argue with yourself. Put your toothbrush down, lift your floss, use it.

what not to do.

Don’t borrow someone else’s stack. Not unless you’ve broken it down and worked out how it fits your life. If your routine is already the same as theirs, then give it a go. But note the differences and consider how you need to make it work for you.

Too big will fall apart before it gets started. Keep your new habit small. So small you almost don’t realise you are doing it. And small enough that it doesn’t create more problems than it solves.

Don’t get carried away. When you complete your new task and it felt natural and easy, it’s tempting to start adding more things to this routine or looking for other points in your day where you can add build new habits. This is where you move to overload and things start to breakdown.

Give yourself time. Let the habit settle into your day, give it a week and if you are still going strong, take what you’ve learned and try it with something new. Over a month, it’s best not to add more than three new tasks or attempt to build more than three new habits.

Every stack has a weak point, that’s what I help with. Book a free introductory call and we’ll find yours.