Cut out the hamburger into whatever shape you like, and cook it in the oven (the shape holds better than when you cook on a pan). Decorate with ham for the eyes and nose.

Thinly slice the cucumber with a peeler, sprinkle with salt then remove the excess water. Wrap up the potato salad with cucumber.

I made cuts into the apple in a criss-cross of a few mm intervals, and just removed the skin in order. It is simple.