Most clients verbalise progressively stronger statements of their desire, ability, reasons and need for change, and this can lead to the emergence of commitment language Miller & Moyers, 2006; p10).

Statements of commitment to change should be reinforced by use of the OARS techniques.

When statements of commitment to change are expressed confidently and ambivalence is less prominent it may be time to move on to the question of ‘how’ to change and leave behind questions of why [see Note A8.1].

The usual procedure at this point is to offer a transitional summary of change talk (desire, ability, reasons, need) that the client has offered for making a change, and then to ask a key open question, the essence of which is ‘What next?’  (Miller & Moyers, 2006; p10).

If the counsellor has timed it right the client will be ready to discuss how change can occur. Now is the time to be curious about how the client envisions change happening, and what unique contributions s/he can make to that change.

Planning is the last of four (4) main processes used in MI, which build upon one another to support the client in their shift towards change. The first and foundational process is engaging, the second is focusing, the third is evoking, and the fourth is planning; [see Note A8.3]

The planning process involves setting goals and articulating actions that will be taken towards the goals.

The role of the counsellor is to help the client frame goals and actions that are specific, achievable and relevant [see Note A8.2]. With the permission of the client this may involve exploring the utility of different types of expression but should not cross over to suggesting any particular goals or actions. It is the client who decides what is needed and how to proceed  (Miller & Moyers, 2006; p10).

Once a change plan has been developed, a crucial next step is for the client to commit to it.

Change talk varies in its strength of commitment. Expressions with weak commitment involve language such as ‘I guess / think / suppose I will’ or ‘I hope to / will try to / will see about’. Expressions of moderate commitment sound like ‘I plan / expect / resolve / aim to’ or ‘I intend to / agree to / am ready to’. Expressions of strong commitment involve language such as ‘I will / promise / swear / guarantee’ Miller & Rollnick, 2010).

The work of the counsellor is to recognise commitment language, reinforce it when it arises, and evoke stronger expressions of commitment.

Clients often need some time to prepare for change without committing to it [see Note A8.4].

Evoking stronger expressions of commitment to the change plan generally requires revisiting some of the strategies described in Elements A2 to A6, but with a focus on the particulars of the change plan rather than change in general.

Note A8.1 Knowing when is the right time to make this transition is difficult, and an important skill, but once a client is ready to discuss change it can be counterproductive to continue exploring motivation for change Miller & Moyers, 2006; p10).

Note A8.2 A Practice Element drawn from Cognitive Behaviour Therapy describes these types of specific and achievable goals in detail 

Note A8.4 Do not press immediately for commitment. Doing so prematurely can undermine behaviour change Miller & Moyers, 2006; p11

Full reference list here