This is a commonly used technique.

In order to shape a behavioural change it is important to minimise the likelihood of a young person experiencing failure.

Thus a target is broken down into small achievable steps... let the young person guide you about what they believe is or is not achievable. Use Rating Scales to help structure these conversations, aim to develop a graded hierarchy of difficulty. The key here is to find enough steps and to get into detailed discussion about which variant of a task is likley to be more or less anxiety provoking. Moving up this ladder of steps is the process known as Graded Exposure. This sort of work follows very well from the use of ABC Diary-keeping, and goes alongside relaxation work such as Progressive Muscle Relaxation.

In substance use:

Moving from smoking 12 joints a day to abstinence may be better achieved by concentrating on smaller steps:

"So you smoke with your mates usually, and we have agreed that amongst your mates you have the reputation as the greediest cannabis smoker around! What if you were to start by trying to take just one, max two, drags on the joint each time it comes around, rather than the four or five you say you take at present. That way your mates won't be upset by you, adn you'll get to cut back a bit... how would that be?"

"What if you were to cut back from 12 joints a day to 10 joints? How difficult would you find that on a scale of 0 - 100 (0 = easy, no problem, and 100 = impossible). Do you want to try that for the next two or three days and then let's talk about whether it was harder than you thought or easier - or about how you guessed it would be."