Make sure you have no glare on the screen, and set the camera to take a photo at least 1/60th of a second or longer..
This is less important with LCD than with CRT, but it's a decent rule of thumb for electronic displays.Tripod is very helpful..
'Be right, fearless, faithfull, and true to others...'T.S. Elliott..
Would you suggest lowering the ambient room lighting or is it better to have the screen illuminated with more than just the lcd backlight ?
If you want only the screen, the lower ambient light would be good(easy to magic wand delete the rest). If you want the device to show you'll need good/balanced ambient light. The screen will give more light than ambient, so don't worry about trying to light the screen..
To give you an idea, I was taking shots of a TV for someone and properly exposed for the screen, the rest of the room was totally black. I had to use flash to show the rest of the TV. If you use flash, make sure the screen is tilted slightly so you don't get a reflection.'Be right, fearless, faithfull, and true to others...'T.S. Elliott..
A lot of the shots you see nowadays are the result of lots of Photoshopping..
To do it well, in the camera....
Get a tripod..
Put a mid-toned grey image, or a full color photo with the clors evenly distributed so there's no big white or black areas, and take a meter reading..
Let's say it is 1/2 second at f5.6 at ISO 100..
Set the camera on a tripod, with these exposure settings..
Frame and focus..
Take a flash unit, and set it so that it provides f5.6 worth of light. Place the flash so it does not wash out the screen, but does illuminate what you need illuminated..
Turn out the room lights, so they don ;t wash out the screen..
Pres the shutter release..
The shutter opens tfor 1/2 a second, the aperture goes to f5.6, and the screen is properly exposed. The flash goes off, propviding f5.6 worth of light to the rest of the subject, exposing it properly, too..
Great... I'll give that a go... thanks a bunch !..