Answer first
Apply Folli-Fix X10 to a dry scalp and let it dry fully. Follow the pack on how long to leave it before washing; many people apply after their shower so it stays on until the next wash. Avoid swimming or heavy sweating straight after applying.
Simplest routine
Shower, dry the scalp, apply, sleep. Wash normally the next day.
Gym and rain
If it gets washed off soon after applying, don't reapply a second dose that day.
Questions
Can I use a hair dryer to dry it?
A cool setting is fine.
Does shampoo matter?
A mild shampoo is enough.