Question: [![enter image description here](https://i.stack.imgur.com/vXXGd.png)](https://i.stack.imgur.com/vXXGd.png)

How can I smooth all crown but don't smooth the top of the crown? I did a subdivision surface, but this didn't work. All crown became smooth and changed form.

Answer: 
add a subsurface modifier, select some edges and crease the edges
[![enter image description here](https://i.stack.imgur.com/OtpAU.png)](https://i.stack.imgur.com/OtpAU.png)

[![enter image description here](https://i.stack.imgur.com/XxlfS.png)](https://i.stack.imgur.com/XxlfS.png)

it's a little easier of you crease the entire thing, then select a few edges and reduce the crease where you want it softer or rounder. 

creasing is quite versatile :D

[![enter image description here](https://i.stack.imgur.com/lor0L.png)](https://i.stack.imgur.com/lor0L.png)
Add in more loop cuts on the subsurf mod. That should do it. I take it that smooth shading doesn't work?