First of all, the photo is of the tools that I use, with the exception of the poker tool.  That is the third from the top.  I use the X-acto knife instead for putting my pattern on the pumpkin.  I use the various blades shown for carving different areas.  I use the carving tool, (second from the top) for pulling away meat to get the different shades.  I use the top saw for cutting all the way through the meat.  Not shown are a jigsaw and a scraper.  I use the jigsaw to cut the top/bottom out,  (which ever I am doing on that pumpkin), and to cut the area out for the light to go in.
    This is not to say that you can't do it with other tools such as one of the kits you buy at the store or from Pumpkin Masters.