• Use the freshest produce you can find, and freeze it as soon as you can—the quicker the better.
• Make sure to wash and dry everything thoroughly. Remove pits and cut into uniform sized pieces.
• Use containers, freezer bags or a vacuum seal system—and remember to leave headroom for expansion.
• When ready to use, defrost in the refrigerator.
There are several approaches to freezing fruit: packed in sugar, packed in a simple sugar syrup, or (my preference) naked. Many experts suggest that freezing with sugar helps to better preserve the flavor and texture of fruit. While once defrosted much of the sugar can be carefully rinsed off, but pure-and-simple still works wonderfully. To pack in sugar you only need to gently combine the prepared fruit in sugar, let stand until the fruit begins to release their juices, then pack for freezing. To make a simple sugar syrup, heat 3 cups of sugar with 4 cups of water over medium-high heat until sugar has dissolved, about 5 minutes. Let cool and pour over prepared fruit to cover, and pack for freezing. The best method for freezing fruit au natural is to prepare the fruit and spread out on cookie sheets to freeze. Once frozen, pack in freezer bags.
Freezing vegetables is not quite as straightforward as fruit. Although just as easy, different vegetables respond to different methods; some do better cooked, some better raw. There are several excellent web sites that provide specific advice for different vegetables. Garden Guides has one of the most comprehensive guide to freezing vegetables.