... use only 3 or 4 small 1" squares. Make sure none of the squares are positioned on removable covers (e.g. disk or memory upgrade covers).

Large Velcro strips can be overkill and it can be really tough to lift off a rigid device like a tablet if there's a big area that can't be "peeled" off. The amount of grip in sheer or straight pull (without peeling) can be surprising. Been there done that, years ago, with a laptop at that time.