There are now 20 tips for Civil 3D in the Civil Engineering Community. I have found these are helpful for learning or recalling tips and tricks. As with just about everthing in the community pages, we can rate the usefulness of an item with a 5 star rating system.
Here are a few tip titles (along with their current ratings):
Increase performance when working with surfaces 5 STARS
Improve Drawing performance 4 STARS
Logging into Vault automatically 3 STARS
Importing LandXML data 4-1/2 STARS
Quick Profile 5 STARS
Note: In it's first week over 700 members have joined the community.