If you intend to have your shredder on the floor, look for one with a simple vertical mouth that will be best for feeding the paper in. If you plan to place the shredder on your desk, an angled mouth is better.
For household safety, make sure to unplug the shredder and place it out of reach of children and pets when you are not using it.
Many manufacturers recommend lubricating your shredder twice a month, using special shredder lubricant.