1) turned off everything in the Customization section at install
2) Used http://pxc-coding.com/portfolio/donotspy10/
3) Used https://github.com/10se1ucgo/DisableWinTracking
Then, I installed a traffic monitoring tool - and surprise surprise - I still found some stuff trying to randomly connect to Microsoft's servers, similarly to what Peter Bright from Ars discovered (btw, "telemetry" can only be fully disabled on Enterprise version of Windows 10):
http://arstechnica.com/information-technology/2015/08/even-w...
I blocked those, too, and for now the Windows 10 spying monster seems to have settled down - BUT - new story points to the fact that you won't even know what Windows 10 updates will do in the future. That means that on machines where they see they can't spy on you anymore, they could push an update to bypass those protections and still spy on you.
http://www.theregister.co.uk/2015/08/21/microsoft_will_expla...
Windows 10 really seems to be designed based on an NSA/law enforcement's wishlist. Any security or privacy measures you might take on it can be rendered useless by an update, and some articles even say Microsoft gets all of your typed keys (so all passwords).
http://localghost.org/posts/a-traffic-analysis-of-windows-10
When I find some time these days, I'll wipe Windows 10 and never look back.
I dont normally like to go meta and talk about voting, but this is the worst example I have probably ever seen.
This one looks interesting but I'd be wary of using it unless source code was available.
The site it is hosted on doesn't appear to have much in the way of info about the author or anything either.
So, there's plenty of checklists out there, but none of them is actually useful at the moment.
I have no use for Cortana, so for me, it's nothing more than an annoyance to be disabled. But for others, it might be the one reason why they upgraded to Windows 10. Likewise, some tutorials out there advocate disabling Windows Defender, but I consider (at least some parts of) Windows Defender to be a legitimate feature.
I'm trying out Windows 10 in a VM, and so far I've managed to disable: everything in the privacy control panel, advertising ID in Edge, Cortana, OneDrive, web search from the taskbar, feedback, telemetry, and the half-crippled Start menu. Now it's just a slightly faster and flatter Windows 7. I'm not sure if I'll ever let it out of the hypervisor though.