Preheat oven to 300°F. Trim crusts from bread and discard. Lightly butter both sides of each slice (or, if you prefer, first blend butter with crushed garlic). I often substitute fruity extra-virgin olive oil for butter, sometimes plain, sometimes mixed with 1/4 teaspoon crushed garlic. Because bread absorbs more oil than softened butter, 1 1/2 tablespoons oil is about right. Cut each buttered slice into 1/3-inch cubes and spread in a single layer, not touching, on an ungreased large baking sheet. Slide onto the middle oven shelf and toast about 15 minutes until pale tan. Use croutons as the recipe directs.