A bright orange pumpkin painted on each cheek. Black paint used to paint eyes, nose and mouth. A light grey would be used to show the ridges of the pumpkin as well as its outline.
An alternative would be to do a full face pumpkin with an orange face base (blending a darker orange shade over cheekbones), black triangle shape over the eyes (extending above and below the eye area), a black nose and a large black mouth (need to cover more than just the lips).
Halloween face painting idea 2: skull
A full face design. Has a white face as the base, large black 'panda' eyes, black and white vertical stripes on the lips (with the white stripes wider than the black ones) and a trickle of red from one side of the mouth (to indicate blood).
Halloween face painting idea 3: vampire
A full face design. A white face base, bright red lips, fangs coming out of each corner of the lower lip (outline is light grey, fill is white, and tip is red to denote some blood), eye lids are smoky grey (right up to and over eye brows), eye brow then exaggerated with black sweeping strokes.
Halloween face painting idea 4: bat
A full face design. A white face base, bat's face painted on forehead above the nose (it's in black with light grey for eyeballs, and for some definition in ears); the bat's body is painted in black on the nose and ends at the base of the nostrils (use different shadings of black; the bat's wings extends out from head and body and covers the eyes curving up towards the temple and down the outside of the eye to mid cheek (again use different black shadings and some fine dark grey strokes to paint some definition into the wings); the lips are painted in dark grey with an exaggerated upward curl at the corners.