Starting with the Android N Developer Preview, Google began posting OTA images for devices in the program. It is faster than waiting for a staged roll out and less complicated than flashing a factory image that completely wipes data. Google has now posted (via Android Police) OTA images for all devices currently receiving monthly updates.
Users need to first agree to Google’s terms and conditions before being able to see the OTA images. The site lists step-by-step instructions on how to apply the update once ADB is installed. Google advises that users should first backup personal data and that USB debugging should be disabled when a device is not being updated.
Links to OTA updates are often grabbed by users as they come out. Google providing the OTA images directly is much safer than trusting links posted in forums and other communities. With the N Developer Preview, OTA images are often posted shortly after an update is announced. Hopefully, the same will be true for the regular version of Android.