Slice the crostini and top with cream cheese.
Shape the pumpkin out of red cheddar slices using a heart-shaped cookie cutter first, then trim with a glass to get the rounded base (I used a Pac-Man cookie cutter).
Peel some cucumber for the stem.
If you want to add dimension to the pumpkin, as I have done, then you can shape a piece of cheddar for the middle section and two pieces to the side.
Place the pumpkin on top of the crostini and add candy eyes.