I pop into the nearest dark alley I can find that seems empty.
Perception: 1d20 + 5 ⇒ (3) + 5 = 8
Once found, I unroll a bag from backpack containing my disguising. I spend some time putting molding on a pair of elven ears, a wig, and some other tricks to make me more elven in nature.
Disguise: 1d20 + 10 ⇒ (14) + 10 = 24