Melt 1 cup of chocolate chips in a heavy 2-qt saucepan over low heat stirring constantly; remove from heat. Stir in margarine. Stir in whipping cream and liqueur. Refrigerate 10-15 minutes, stirring frequently, just until thick enough to hold shape.
Drop mixture by teaspoonfuls onto cookie sheet. Shape into balls. (If mixture is too sticky, refrigerate until firm enough to shape.
Freeze 30 minutes.
Heat shortening and remaining 1 cup of chocolate chips over low heat, stirring constantly, until chocolate is melted and mixture is smooth; remove from heat.
Dip truffles, one at a time, into chocolate. Return to foil-lined cookie sheet. Immediately sprinkle some or all of the truffles with your desired toppings (nuts, cocoa, coconut).
Refrigerate about 10 minutes or until coating is set. Drizzle some of them with a glaze of the powdered sugar and milk if desired.