For tender, flaky pastry, use a pastry blender or a pair of knives to cut the chilled butter into the flour. The blades of the pastry blender quickly combine the butter and flour, forming a dry mixture that resembles coarse meal. If using two knives, hold a knife in each hand. Then pulling the knives in opposite directions with the blades passing close together through the butter and flour.
Try this Kitchen Shortcut with Blueberry Cobble Recipe.