It is kind of a silly question really to ask How to use a graphics tablet, but some people may be interested in the process of using the tablet or pen display to make digital images. I guess the best way would be to break down the process into a series of steps.
1. Get connected! Some graphics tablets connect using a serial connection or Bluetooth, but the majority of modern devices communicate with the PC or Mac via a USB cable. Make sure you have the tablet plugged in and powered on.
2. Choose your weapon! The tablets can be used with various styluses, pens, mice and input devices. Even the pen and stylus supplied with most modern tablets will also be supplied with a range of nibs or brushes which will make the strokes on screen different. The stylus or pen supplied with the graphics tablet will most likely be covered in an array of buttons and selectors which you can use to perform functions within the application you are using. Familiarize yourself with these too.
3. RTFM! Make sure you read all of the documentation that comes with your graphics tablet. It will tell you how to use and adjust the tablet to your needs. Some graphics tablets or interactive pen displays will allow you to adjust the angle at which you use them. Just this simple adjustment can make all the difference when using the device. There will also be software settings that can be tweaked and changed to make the experience more authentic.
4. Install the disks! As some of the popular graphics programs such as Adobe Photoshop come with a plethora of tools, settings, brushes and effects it is important that you install the drivers or plugins for your graphics tablet before you start. If you are using a software package that does not have a plugin supplied by the tablet manufacturer there will most likely be a system wide set of parameters and settings you can adjust to allow you to create better images.
5. Create! This is the most obvious part of the series of steps. Once you have installed the device, installed the disks and software and chosen the correct settings for you, the next part is to open the application you wish to use and get busy. Try choosing different brush sizes and shapes if the application supports it and also experiment with the levels of sensitivity that the graphics tablet and stylus allow you to use. These are perfect for making a nice watercolor painting or building up an image in layers.
The author runs a website where you can read a graphics tablet review on products such as Wacom, Vistablet and Genius. You can also read several more guides on getting the best out of your graphics tablet and which one to choose if you are buying.