There are two basic techniques used to prepare fruit sauces. The first requires delicate, softly textured fruits, such as berries and melons. These are simply pureed and sweetened with powdered sugar. For the second method, firmer fruits, such as peaches and nectarines, are poached in a sugar syrup flavored with lemon juice and vanilla bean before being pureed. To accent the taste of any fruit sauce, liqueurs, brandies or fresh fruit juices can be added. Pear brandy, for example, perks up pear sauce, and melon liqueur is a natural with honeydew melon sauce. Do not hesitate to mix and match, too: Peach brandy, for instance, enhances apricot sauce, while either raspberry brandy or kirsch adds zip to a sauce made from strawberries. Begin by adding a teaspoon of brandy or fruit juice or a tablespoon of liqueur at a time, tasting and adjusting as you go. A pinch of spices also lends an interesting twist. The basic fruit sauce is as simple as that: All you need do now is decide how to present it. Try swirling some peach sauce on a plate, topping it with a scoop of vanilla ice cream and garnishing with raspberries. Spoon berry- studded whipped cream onto a slice of cake and encircle it with a ribbon of fresh berry sauce. Create a colorful fruit salad of kiwi slices, strawberries, figs and nectarines and dress it with an exotic mango sauce. Or ladle sauces of contrasting colors side by side, add rounds of ice cream and decorate with sliced and whole fruits in the Apricot and Blackberry Sundae for a cooling and colorful finale to a meal.