How can I get holes in curved surface in a way that keeps the surface smooth and has a hard edge at the hole.

Hi, PixalZA. Your work is so clean and beautiful. How did you do this? I'm new to subD and Maya modeling. Any tips you have would be greatly appreciated.

So far I'm having real trouble adding geometry in a way that doesn't distort the overall surface.
What tools and techniques do you use?

https://simplymaya.com/forum/attachme...1&d=1320606336