Practicing good hygiene is the best way to avoid contracting molluscum
The best way to avoid many infections including molluscum is good hygiene. You should start with hand washing. Frequent hand washing is something that you should get in the habit of doing to eliminate germs picked up from other people. When treating someone with molluscum or treating yourself you should wash your hands before and after cleaning the infected area. This will prevent the spread of molluscum from one part of the body to the other and the from one person to the other.
Also you should try not to pick or scratch at infected areas. This will also cause the infected area to get worst and increase the changes of it spreading to other parts of the body.