Answer first
Full-scalp SMP looks most natural with a close buzz cut, because it mimics short stubble. Density SMP works under longer hair to reduce see-through. Your hairline shape and style are planned together at NPM so the result suits your face and age.
Buzz cut
Keeping hair at a similar short length to the dots makes the look consistent. Many clients trim every few days.
Longer styles
If you want to keep length, density SMP adds shadow under hair rather than recreating a shaved look.
Hairline
A softer, age-appropriate hairline usually looks more natural than a sharp, low line.
Questions
Can I change style later?
Partly. Discuss future plans before your first session.
How often do I trim?
With a buzz cut, many people trim every few days.