Using tasking should be part of every session and definitely should be used before you see the client for the first time. It is also very important to make sure you disclose that you will be giving the client tasking as part of the session. The client should know and you should be 100% clear on the importance of the tasking. If the client does not fully appreciate that the task is part of the process and they are responsible for completing the task they will not put the value on it that they need to have. If their investment is not clear, they will do a half-arsed effort and be doing it for the wrong reason.
So let's look at the first point "You want to make sure that the task brings unconscious behaviors conscious". You want to make sure that the client knows the problem they have, often the the problem the client has is very unconscious. They may be coming to see you because someone has mentioned to them that the behavior is not helping them. Could be a career issue like sweating when giving presentations. Or it could be a recent promotion and they have a strong anxiety about being able to live up to the expectations. Or it could be picking their nose in public! Once the client is tasked to observe the behavior or problem often the task can solve the problem as the client will have a massive shift and effectively re-frame themselves. This should not be expected but does happen on many occasions.
The second point is to have the client to then observe their behavior. More than just observe their behavior they need to document it in details (the more detail the better). They record the issue, as it happens, then looking over it after it has happened or at the end of the day they get to really observe the issue.
The third point, tasking allows you to gather a lot of information about the client and the clients problem. Having the client observe the problem and document it is great. Having the client send you the information before you see then is gold. It saves a massive amount time with you learning how they do the problem ahead of time. This gives you a great insight into the clients thinking and patterns. You get to see the clients struggles and repeat behaviors. This is why it should be considered part of the process.
Obviously this leads the the forth point "it allows you to get great insight into how the client does the problem" with a effective task you get to see the trigger, the process and the end result of how they feel about the task. This way you are already two thirds through the process of the session and you have a very clear document of how the client does the problem.
Naturally, this causes the client look at their problem, dissociated and from the angel of "how does this behavior serve me?" This is how tasking can then allow the client to make a shift, if they are tasked for long enough to observe the behavior they will be so over watching themselves document the behavior they will start to reject the negative behavior!
To really understand the thinking behind tasking you need to really create an ordeal for the client to do. It is meant to be challenging, push their buttons or push them out of their comfort zone. It should always be appropriate and ethical and legal. It should also empower the client.
I have heard of many practitioners giving tasking to clients that would just reinforce the problem and not help the client in any way. Clearly the practitioner had no true understanding of what is tasking. The worst example was a lady that had not been in a interment relationship for over 15 years, the practitioner told her to go and have a one night stand! That does not serve anyone let alone is it ethical.
So what is tasking? Tasking is an ordeal that the client does that demonstrates that they have investment in solving the problem, that they are willing to following instructions. Tasking is something that the client does that empowers them and gives you the coach/practitioner and the client insight into the motivation and or how they do the problem and why they do it. When done really well, this process can lead the client to changing the behavior just through the process of observation.