Always store video tapes in their cases away from the dusty atmosphere. There are a number of blank video tapes on the market today. Many poorer quality tapes shed the oxide layer which in turn causes damage to the video heads. Using worn tapes should be avoided as they introduce unnecessary wear to components and they lessen the life of your video heads. In a video recorder the head wear is directly related to hours of use AND the quality of tapes used - it is not necessarily due to the age of the recorder.
Adequate ventilation is important.
Moisture can accelerate head wear. Replacement of the video heads is costly. The demagnetising of tape path component and head assemblies and lubrication of key items such as idler wheels and gears, can only be performed by a competent service person. When your picture on a playback starts to show significant snow or streaking, this is the time to have your video recorder cleaned. These products can never do the job as well as a trained technician and can instead create additional head wear, reducing the life of your video heads.