Inspect the feet of the washing machine. If, for some reason, the feet are uneven, place pieces of cardboard underneath to bring them to an even level again. Rapid vibration causes uneven feet to bang against the floor, making a lot of noise and putting wear on your floor tiles.
If you don't want to use cardboard, have someone help you lift the washer and install the rubber feet onto the existing feet. The rubber replacements should slip on. The bottom of the washer should be no more than 1/2 inch from the floor.
Pull the washing machine out from the wall. Allow 1 foot of space for room; this reduces the likelihood of the washer hitting the wall.
Avoid filling your washer too full. A top-loading washer should contain a pile of clothing no more than 3/4 the height of the drum, and a front-loading washer should contain no more than to the top of the agitator.
Balance the load. Uneven weight distribution will make the washing machine rock, and bring its bearings and drum out of alignment. Keep the clothes' weight evenly balanced on all sides of the drum. If it sounds like your washer is off-balance, immediately stop it, and open and redistribute the clothes before starting it back up.