Post an example or two.
Get familiar with the adjustment brush. Use it to clean up the selected areas, reducing exposure and highlights, and maybe increasing saturation if necessary. If you burn down very overexposed areas, often it'll show as grayish instead of the full normal color.
Use multiple adjustment applications of the adjustment brush to increase the effect in selective areas.
Add color to the adjustment brush (or to a new one) to improve, increase, or change the color in selected areas. Sometimes you have to choose a color that's quite different than your desired end result; when the color stacks with what's already there you often get unexpected results.
For increased clarity, you'll use the Contrast, Clarity, and Vibrance sliders, as well as a little bit of the Sharpening spiders. You can also adjust the white and black points using the whites/blacks sliders. However, there's no substitute for a good original shot: Proper exposure, proper focus/DOF, and (perhaps most importantly) appropriate lighting.