When much of your working day is spend looking at a computer screen, it is important that it be at the right height. This means that your head should be in a comfortable position and that your eyes are at the level of the screen. A simple and affordable way to ensure this is to use a riser on which you can simple place your screen. Another option would be an adjustable mounting arm, but that is a more expensive solution.
I like how this model also provides a shelf and a drawer:
Wood monitor riser:
Wood monitor riser pictured: Victor Technology 11755 Monitor Riser, 13 in.x13 in.x6-1/2 in., Midnight Black