The documentation that comes with the One is non-existent, and while all of the following information is out there somewhere, it's not really condensed in an easy package anywhere, so hopefully this helps someone out there if they're not getting the full experience. Any comments on well-used Kinect features I might leave out are more than welcome.
After setting up a profile, the One should recognize you, but at first it often will not. Whenever this happens, go to sign in, and then "I wasn't recognized". Doing this 3 or 4 times should get you recognized properly each time. This way you ensure that your pins and presets load properly when you step in front of the sensor.
Calibration is really important. After I calibrated properly, my One went from something I was yelling at while wanting to chuck it out a window, to a really cool hands-free entertainment hub.
To calibrate, go to Settings, and then Kinect. Once the Kinect screen comes up, go to "I moved my Kinect sensor or I'm having trouble with Kinect". You'll have a couple of different outcomes here. Either Kinect will see your floor, or it won't. If it can't see your floor, you may need to move your Kinect sensor. If the floor is visible, keep going until it sees the floor. Skip the audio portion, and go back through the same process, because Kinect probably set your floor at the wrong height. Set the floor height until your feet are no longer green, and then move on to the audio portion of the set up. At the beginning of audio set up, you are told to be sure that your speakers are turned up. DO NOT turn up your speakers. This will likely lead to you shouting at your Xbox in frustration. Instead, turn the volume down, way down, and then start the audio calibration. After checking background noise and speaker volume, it will tell you that your speakers are too quiet. Turn them up slightly and try again. Keep doing this until you pass the volume test, and then go through the rest of the audio calibration. Now you'll be able to speak to your Xbox in a normal tone.
To turn the One on, say "Xbox on".
To turn the One off, say "Xbox turn off", and then "yes" when prompted.
The two best general navigation voice commands are "Xbox Select" and "Xbox Go To...". Xbox select will show you every voice command link on screen in green. It's important to understand that the One will only respond properly to the exact phrase. For example, the phrase to turn Xbox One on is "Xbox on", and the phrase to turn it off is "Xbox turn off". However, if you say "Xbox turn on" or "Xbox off", nothing happens, or the One interprets it as a completely different command. Once you learn the phrases the One is looking for, "Xbox Go To..." is particularly powerful. This will take you to anywhere from anywhere, but you have to get the phrase right. Sometimes the phrases are rather confounding. A good example is Kinect Sports Rivals Preseason. Let's say you're looking at games in the game store and want to play Kinect Sports. You could trudge your way through the menu or simply say "Xbox Go To Kinect Sports Rivals Preseason". Not Kinect Sports. Not Kinect Sports Rivals. You have to say the WHOLE THING.
To completely lose the controller, you'll also sometimes need to use gesture navigation. Gesturing can be difficult at first, and takes some getting used to. The first key is to not move your hand very much. Your hand's equivalent of a mouse pad is a box in space near your shoulder roughly one foot high, a foot and a half wide, and half a foot deep. This will vary depending on how far you're standing from the sensor. But that's probably at least 3 or 4 times smaller than your screen, so for every inch you move your hand, the hand icon will likely move 3 or 4 inches. There are six gesture controls, but you'll really only use three to navigate.
Selecting is the one you'll probably use most. Unfortunately, at the moment, for some unknown reason, not every menu option has a corresponding voice control. When this happens, you'll use the select gesture to select your menu item. You do this by holding up your hand, open palm facing your TV, until the One recognizes it as a cursor. Move your hand to the item you want to select, then push your open palm toward the screen until the hand icon fills in completely white, and the intended menu item pulses. Lastly, pull your hand back toward you slightly, open palm still facing the screen to open the selection. You'll have to push forward about 6 inches to select something, but only back an inch or two to activate it.
Next is scrolling. Once again, raise your open palm to the screen until your hand icon appears. Now close your hand until the fist icon appears. At this point, you can scroll the menu either direction(or up and down if you're using it with Internet Explorer for example)by moving your fist. Open your fist to release.
Lastly, there is the open system menu gesture. This is the equivalent of pressing the menu button on the controller. To do this, start with an open palm. Push your open palm forward and hold until a ring appears around the hand icon. Once the progress ring completes it's circle, the system menu for the selected item will open.
This is where things start getting pretty cool. Assuming all things go right, you should be able to control certain aspects of the devices that you connect to the One through HDMI. I used to work in cable installation, so I have years of experience with control codes, and I can tell you right now, there are devices that are not going to work properly with this no matter what, so don't be too surprised if you have a problem. This feature should work for the vast majority of users, though.
You can control your TV with voice commands! Go to settings, TV & One Guide Settings, and then Devices. Here you can go through the code searches to interface the One with your devices. Once you have control of your device(s), back out to TV & One Guide Settings, then go to Power Settings. There you can decide which devices the One turns off and on. In addition, once configured, you'll be able to change the volume of your TV or receiver with voice. You'll also be able to interface with your cable box, if you have one, with voice commands as well to change channels, etc.