Have you ever had to hand draw objects into your profile or section views for reference in Civil 3D? Now thanks to Civil 3D's Project Objects to Profile View and Project Objects to Section View functions, it's as simple as creating a solid and projecting it. I use this to project power poles, houses, trees, underground pipes, utilites, etc., to check for horizontal and vertical clearances.
As an example for poles, draw a circle in plan view and be sure to set its center z point at the correct elevation. Once that's done, use the Extrude command to extrude it to the desired height.
In the Civil 3D ribbon, go to the Home tab and find the profile and section views panel. Use the dropdown from the Profile View or Section View menu to get to the option. Pick your extruded 3D object and the corresponding view to see its projection. You can use Sweep, Box, Cylinder, Cone, Sphere, or any other Civil 3D solids tool to get what you need.
This tip saves time when you need non-sampled objects to show up accurately in a normal or vertically distorted view.
Notes from Cadalyst tip reviewer R.K. McSwain: One big advantage to this tip is that the projected objects are part of the profile or section as opposed to manually drawing plain AutoCAD objects.