Increases your VMC speed...........Landing gear up, unfavorable c.g., flaps up, takeoff power set, windmilling prop, banking more than 5 degrees into the operative engine, hitting VMC out of ground effect.
Decreases your VMC speed..........Gear down, forward stable c.g., flaps down, banking equal or less than 5 degrees into the operative engine, low power, feathered prop, hitting VMC in ground effect.
Simple way to remember, if its more stable, VMC will be lower, less stable, VMC is higher.........................