I'm really having a lot of trouble figuring out how they balance. They're generally depicted having their bodies raised similar to how a cobra lifts it's head. But cobras don't move around like that very much, only when there's something to strike at. And their head/neck portion only makes up a small portion of their body length, giving them more than ample counter-weight. But with most naga designs, the tail portion usually doesn't exceed 1.5 the length of normal human legs. That isn't much counter-weight to work with, when most of it is laying flat at a 90 degree angle to your waist. This means that a naga's tail section would either have to be extremely long, (Making them very difficult to work with, art-wise) or somewhat shorter and quite thick. It raises questions, like, do they move around with their body raised, or do they more crawl along the ground? Do they hunch over in an 'S' like a cobra, or are they more upright? How do they fight? Can they jump? Can they swim? If so, how? Most land snakes swim by throwing themselves across the surface of a shallow spot, hoping they reach the other side before they sink. Do they use their arms as part of how they move around, or do they avoid touching the ground as such? Do they slide smoothly along the ground like real snakes, or do they propel themselves by coiling and zigzaging? A lot of naga drawings give the impression that their body is sort of floating, while the tail section simply drags along behind them. This makes sense if you interpret them as deities, but I'd prefer to think of them as animals, or at least mortals of some sort. I think these ones got it really close to right:

[link]
[link]
[link]
[link]

--
The only thing worse than living, is dying.