That's how we do in our studio intersections, caps and further round stuff in 3d. No magic, pure essentials actually. But it's our way to get clean, hassle-free geometry that renders nicely.
The tutorials requires some basic poly-modelling skills and should be easily applicable to most poly-modelling tools.
The software used is 3d Studio Max 2012, but can be applied to any earlier Max-Version or other 3d application.
Hope you like!