In a slip, the rate of turn is too slow for the angle of bank.
The aircraft's tail is slipping in towards the direction of the turn. To correct this either decrease the angle of bank or use more rudder to increase the rate of turn ( or both).
In a skid the rate of turn is too fast for the angle of bank.
The aircraft's tail is skiding away from the direction of the turn. To correct, increase the bank angle or use less rudder to decrease the rate of turn (or both).
Ball in = SLIP = Stick Less Increase Pedal
Ball out = SkiD = Stick inKrease Decrease pedal
Well it works for me!