O&O ShutUp10 is a tiny portable tool which makes it easy to tweak Windows 10's many privacy settings.
Launching the program displays almost 50 options, organised into various categories: Security (telemetry, wifi sense, DRM), Privacy (Cortana, input personalisation, app permissions), Windows Update (disable peer-to-peer updates, disable automatic updates) and more. These aren't always clearly described, but clicking any item displays more details on what it does.
There are options to disable only the worst offenders (turn off telemetry, peer-to-peer updates, keep Windows Update and SmartScreen), turn off everything, or tweak individual settings.
ShutUp10 offers to create a system restore point before it makes any changes, useful if your tweaking breaks something important and you need an "undo".
There's also a separate option to restore Windows 10's default privacy settings, which might also be handy if they're generally messed up and you'd like to start again.
O&O ShutUp10 is a quick way to lock down Windows 10's many privacy settings and technologies. This may also be a problem - disabling the wrong setting could cause you all kinds of issues - but system restore support and the "Reset" option make it easy to undo your changes, if necessary.