How can I check the purpose of each step of the care routine and items that can be omitted during a skincare consultation?

I would like to know the criteria by which I can be explained the difference between bundled treatment programs and individual treatments during a skincare consultation. This is not an inquiry regarding specific symptoms or treatment experience, but a general question intended to organize the items to be checked during the initial consultation.

What is the purpose of each step, such as cleansing, exfoliation, extraction, moisturizing, and soothing? Can I select only some or omit them based on the examination results? I would also like to know if programs with the same name can differ in the products, equipment, and procedure order, and if I can be advised on alternative methods if the treatment is not suitable for my skin condition.

Could the quote be broken down into consultation fees, costs per stage, optional items, and VAT? I would also like to know the procedure for stopping or changing stages if the stimulation becomes uncomfortable, and how the cost changes in those cases. I would also like to inquire if it is possible to proceed with one session first to assess the patient's response and then discuss the next plan, rather than scheduling multiple sessions in advance.

Finally, it would be helpful for my preparation if you could let me know how instructions are provided regarding cosmetics to rest from before the treatment, the interval between procedures, and post-treatment cleansing and sun protection.