Crystals are normally treasured items and great care should be taken when cleaning them. The consensus is that crystal is best washed by hand to minimize fogging and streaks. To clean crystal you will need to have on hand the following: vinegar, mild dishwashing liquid and warm water.
Hand wash the items one by one in warm or lukewarm soapy water. Washing fine crystal in the dishwasher may result in chipping or breakage so why take the chance. If the crystal is of the decorative kind, dust first before washing. Once you are finished washing the crystal, rinse thoroughly in a mixture of warm water and vinegar. The vinegar will prevent fogging so that the glass dries clear and streak free. Never wash crystal in warm water, followed by a cold rinse as the change in temperature can result in cracking of the pieces.
Those crystals with decorative rims should not be left to soak for extended periods as the silver or gold edging will start to fade or strip.
Some crystal containers, such as vases and decanters will over time develop stains around the bottoms or rings which normal washing may not remove. To remove these types of stains, pour vinegar into the crystal vessel to the level of the stain and leave overnight. The acid in the vinegar will act on the stain without damaging the crystal. Next day, add some rice grains (uncooked) to the vinegar and shake vigorously; this will serve as an abrasive and loosen the stains. You may to repeat this action depending on how badly stained the item is. Once you are satisfied, rinse thoroughly. However, if the stain will not budge, try some commercial solutions but make sure to read the instructions carefully to ensure that that they are safe to use on crystal.
Even if you do not plan to wash treasured crystal often, a little light dusting is good to keep dust to a minimum. When you dust make sure to lightly dust the glass with a feather or other lightweight dusting so as not to scratch the surface. Even the tiniest speck of dirt can etch lines into the surface of crystal.
Once your crystal is clean, know how to store them safely and properly. They must be never be stored wet, plus it is best to keep them from touching, especially other glass containers. Also, do not store crystal stemware rim down. The rim is delicate and will become damaged.