Camera Effects

In my media course/ animation course at college (2 years ago) we had to improvise and try to create some cool effects
for e.g.

we set up a video camera and filmed the background without an actor in front of the camera, we then got the actor to stand in front
for a short period of time, we then edited and added a fade transition , so it appeared that the actor had just fazed in/appeared from nowhere

we also tried messing about with toy sizes, for eg had the actor to the left of the screen (far away) and had the toy/model to the right of the screen (close to the camera) both in shot, and made them interact , the actor had to imagine a 6-7 foot superhero in front of him
the overall effect was to make it seem they were next to each over

i think it worked out rather well, i will make a new video with these in and upload it to my youtube account (omg i just got an idea)
when i have finished the movie i will upload a link