Boil potatoes for ~20 minutes, until soft or easily penetrated with fork.
Drain most water (leave at most a quarter cup of the starch water, less is fine. Though you may need more milk)
Add butter, milk, and seasonings
Mash and mix until all potatoes are your preferred consistency, and incorporate all seasoning. you may have to add aditional milk. Feel free to tweak the seasonings, and measure with your heart.