When you complete any song, you're brought to a mini studio with a video replay from your performance. Go to the "FX" section on the left and apply effects.
Apply any effect for this achievement :
Apply the Slime effect (the stick figure with a green thing over it, second in the top row) for this one :
Apply the Big Head effect (the stick figure with, well, a big head, third in the top row) for this one :
Apply the Ice effect (the one with half the pic white, fourth in the top row) for this one :