Please check out my class this year and classes I did previously.
Endless Corridors with AutoCAD® Civil 3D_ CV422-2 -2010
Diversify Visually with Autodesk Civil 3D_DV322-1 - 2009
Don't be left out in the CODE_CV9314-1 - 2009
The most prolific topic that I discussed was utilizing Conditional Subassemblies, ConditionalHorizontalTargets to complete driveways, sidewalks and ADA ramps. Below is an example of how this works.
Plan view results applying one assembly. Notice the curb is removed from the drive ways, and the sidewalk continues through the walk, but is removed from the road. This is accomplished by simply placing polylines at critical locations. The conditional subassemblies have an option to look for the nearest or the farthest target and associating the correct subassembly. The red polylines placed on the driveway applies the gutter subassembly and the green polyline marks the target for where a region should be placed so no subassembly is applied. More elaborate subassemblies can be developed to utilize conditional subassemblies after each individual subassembly. Have fun and remember to place and test the targets are working, before applying the no target subassembly.