Ski boot issue?

I watch all these videos on ns of these guys doing last second shifties and1-80s right before they land they just seem to twirl their skis around and just have so much control of their skis like their not even wearing skis. The question is how? How do I have that much control of my skis. My foot doesn't move inside my boot, I have tw full tilts but the sole itself shifts depending if my weight is on my shins or heels is that normal? How can I make it a tighter fit without buying new boots? I got them for xmas Any advice helps thanks.