According to the Yogic definition, meditation is as simple as having a single pointed focus. This single point of focus, could be just about anything. The requirements of the environment could be just about anything that allows you a conducive space to maintain that point of focus – this is different for everybody. 

For example, you could focus on the water running down from the tap when your washing your hands, on the water when it enters your mouth, on swallowing the water down your throat, each and all, are aspects of that single pointed focus that ones attention could be focused on. The object of focus, in this case, is thewater itself. 

Although water running from the tap is not a great example, cause we don't really want to be focusing for too long on it going down the drain, eh? Meaning with the whole being environmental friendly and conscious aspect, cause if the purpose of meditation is to build conscious awareness, the means of meditation itself, must of course, be coherent with the efforts of building that conscious awareness itself.