Well, first of all, you need the right supplies, and these include the following:
Double-sided tape
Lighting

click to enlarge
Green Screen
Editing Software
If you already have a professional studio, then you probably have already made the lighting, video editing software and green screen investments. If not, then you can create your own green screen using dye and old fabrics, and you can use lamps as your lighting. These items plus the double-sided tape should cost you less than $20.
The video editing software, however, can be expensive. But, you can always use the free downloads, or you can purchase one of the cheaper programs like Windows Movie Maker.