A component includes a wall with a cold and a hot surface. At least one film-cooling hole extends through the wall for flowing a coolant from the cold to the hot surface. The film-cooling hole defines an exit site in the hot surface. At least one flow modifier is formed on the hot surface and is adapted to direct the coolant flowing from the film-cooling hole and out of the exit site toward the hot surface. The flow modifier extends outwards from and conforms to the hot surface. A turbine assembly includes a first and a second component that define a secondary cooling slot, which receives and guides a secondary coolant flow. At least one flow modifier is formed on a surface of one of the two components and is adapted to enhance the secondary coolant flow along at least one of the two components within the secondary coolant slot.