Your LG washer will be with you for a while. Time will pass and you may need to rebalance the machine to prevent vibrations and keep it running smooth and silently. If you start to notice any abnormal vibration, there are a few things you can do.
Check that the "tub support" has been removed from the underside of your washer. It fits up into the machine and nestles against the bottom of the tub, and could go unnoticed. If it's not removed, your washer will vibrate more than needed.
If vibration occurs inconsistently, it could be that certain loads—and not the washer—are causing the vibration. That's perfectly normal.
Check to see if the load is small or large, and if it consists of mixed fabric types or a large item. It could be that loads are not distributed evenly across the drum. If that's the case, pause the cycle and move the clothes around.
Use a lower spin to minimize occasional vibration.
Make sure the clearance requirements are being met. If they're not, it could cause vibration.
Check for foreign objects under the feet of the unit.
Ensure that your washer is leveled. A quarter of a turn adjustment to the feet can make the difference between a perfectly silent washer and one that is always vibrating.