Many clothes stored for a long period of time attract moths, but clothing made out of animal fibre is at the highest risk. Moth balls have an unpleasant smell, and contain chemicals you may not want in the house. There are plenty of alternatives to mothballs that allow you to store clothing without having to worry about moths.
Many people use cedar to repel moths. The website Green Living Tips, recommends placing cedar blocks or chips around your clothing to discourage moths. You could invest in cedar closets or chests to store your clothing inside. The website suggests you should sand cedar occasionally to keep it fresh, or moths will eventually return to the clothing. Moths may also be repelled by bay leaves, cinnamon sticks, cloves, lavender, and peppercorn. As an alternative to a moth ball, pick one of these alternatives and wrap it tightly in cheesecloth, then secure tightly. Put the cheesecloth in with your clothing, but be sure that the bag doesn't touch the fabric so that you don't risk damaging it.
If you currently have a moth infestation, Oregon State's website says you should vacuum out the storage container or closet where the infestation occurred with a HEPA filter vacuum. You could also vacuum your furniture, rugs, and other places where lint, pet hair, and human hair tends to gather because moths feed on this debris. This should get rid of the existing moths.
Before storing your clothing, clean it according to the manufacturer's label. This will remove any moth eggs that are attached. Moths also seem to be attracted to the human scent, so washing your clothing before storing it will remove your smell, making it less likely that moths will be attracted to it. Make sure your clothes are completely dry before storing them. Wipe out all your storage containers before putting your clothing inside. You should also do this periodically if you're storing clothing long-tern. Wiping removes any eggs that might still be in the container. After you have placed your clothes inside storage containers, make sure they are well-sealed, so that moths won't be able to get inside. If you are storing your clothing in a place where there are cracks or crevices, you can also sprinkle boric acid dust around them to discourage moths from coming inside.