There are a lot of things, from the pin out of the box, use the virtual keyboard, adjust the brightness with the slider and LED notifications in setting. If you can find any additional features, please share it with everyone within this topic.
Similar to Windows 10 on PC and Windows Phone 8.1 GDR2, now you can “pin” as the custom personalization settings related to the display, audio and more to the Start screen. This helps us access to frequently used settings quickly than before. To use: Go to Settings> browse to any item> click on the pins as shown> return to the Start screen will show a new tile appears.
Previously multitasking interface will glide from right to left, while in Windows 10 build 10051, the app will run from left to right like the iOS. This simply changes direction only, it is not much affected at all.
With the Lumia 1320 or Lumia 1520 device screen, you can move the virtual keyboard on a deviation to the left or right hand use. With this shrink keyboard, we can type easily with the convenient manner using one hand. The keyboard can also move to any position on the screen. To use: swipe your finger to the left or right of the spacebar key on the virtual keyboard.
In new Windows 10 Technical Preview build 10051, Microsoft has allowed us to rename the device directly from the phone without going through the computer. To use: Settings> System> About> Device Name> Edit name.
The default Windows Phone only allows us to adjust the brightness level as low, medium, high and auto. Now with Windows 10 TP, you have a slider for adjusting brightness comfortably at any level you want. In essence, previously the slider only available on some Lumia lines, but now all the Windows 10 devices come with this feature. To use: Go to Settings> System> Display.
The battery saver mode already featured on Windows Phone 8.1, but at first we could only choose one option is the generic Battery Saver is activated when the battery low. Now, on Windows 10 Technical Preview, you can select the battery level yourself that you want run battery saver app. To use: Go to Settings> System> Battery Saver.
LED notification feature:
It is noteworthy that most of current Windows Phone does not have LEDs hardware, therefore we cannot use this feature. Particularly, the Lumia 730 and Lumia 735 with integrated LED but it is not enabled on Windows Phone 8.1, which does not mention this component. Hopefully we will see this feature in future updates as well as new Windows phone, and if supported multicolored LEDs such as BlackBerry or Android is better than another.