I'm working a lot with GoPro footage these days, which is fairly neutral but also pretty lifeless in native/flat mode, and a big challenge is getting the colors to look rich and properly saturated. Vegas doesn't have a vibrance plugin, so the goal here would be to duplicate the effect of something like Photoshop's vibrance slider in Camera Raw -- basically something that enhances non-skin tone colors without making everything look blown out or neon-candyish.
For starters I use color curves to just draw a contrast-enhancing curve over the clip. This on its own helps bring up the colors. Then I turn to the Color Corrector Secondary, and use that plugin to modestly boost overall saturation.
Then I add another CCS instance, and this time target a specific color using the "select range" tool. For example, going after the blue in a blue sky. When I've got the color appropriately targeted, I might try adjusting it's hue a little, and then dialing up saturation. Maybe next I'll go after greens and to the same thing with another instance of CCS.
You can also come at this from the opposite direction and target skin tones, and then invert the mask.
Either way works, and has the advantage of staying entirely within Vegas' stock tool set. Especially with GoPro footage there is the danger of banding starting to appear in skies when you push up the vibrance this way. You may find the banding gets a little better if you switch to 32-bit video levels in project properties before rendering out. Or not.
I definitely can't match the quality of Photoshop's adaptive algorithms (esp. DeHaze!) using this stacked Color Corrector (secondary) technique, but this works a lot better than just a basic saturation boost--and it gives some control over individual color hues (for example, if your forest trees look a little too yellow but you don't want to touch anything else)
One other technique I've played around with is using the Unsharp Mask fx to boost local contrast (using larger radiuses). But I eventually gave up on that because it was too hard to predict/control the results.
If anyone else has vibrance tips (working within Vegas' stock set of fx) and you're willing to share, please let me know.