Making circles, domes, or spheres

[Thorin]

This guy shows how to use an online tool to figure out circles, domes, and spheres using an online tool: http://youtu.be/O2YGw3dhnj8

Here's the online tool: http://neil.fraser.name/news/2006/11/17/

[Mr. Analog]

Circles are easy, google "minecraft circle template" and you'll find it.

VASTLY makes building circles easier

[LennyLen]

I prefer this tool for spheres: http://www.plotz.co.uk/plotz.php