Start with your favourite cupcake, make sure it is totally cooled before you decorate it.
Colour some readymade icing orange with gel food colour and roll a lump of it into a ball. Using a cocktail stick make some light indentations around the orange ball so that it looks like the segments of a pumpkin. Then colour a tiny bit of readymade icing with black gel food colour. Shape two tiny black triangles, a tiny circle and a tiny crescent and then use a cocktail stick to position them on your pumpkin so they look like a face, they should stick on themselves but use a little water if they need some help.