Select a pot or container with a drain hole one or two sizes larger than the old pot. When choosing a new pot, pick a pot with a diameter that's only an inch or two wider than the original. A pot that's too large can lead to over-watering.
If the new pot has been used previously, use anti-bacterial soap to kill any potentially harmful organisms left in the pot. Clay pots need to be soaked overnight and then scrubbed to remove the white fertilizer salts around the insides.