Chain Link Fence Gate
This one's probably been done plenty of times, but a good way to make it more believable is to make sure the fence material is as fine as possible—finer than the materials typically used, such as etched sheet metal or micro-mesh. I created this effect for the Men At Work diorama; it was not planned in advance, but came about when an opportunity to model a little junkyard emerged.
After I completely finished the junkyard, I began work on the gates, using the same materials as I had for the fence. I waited because finishing the junkyard scene meant handling things a lot, and I wanted to minimize handling the junkyard and the mechanism. The hinged end of the gates are soldered to extra-long brass posts that drop through the base. On the lower end I attached strip styrene cranks. (In principle, this is identical to the store/business doors. However, I didn't want both gates to swing wide open, nor did I wish to control them separately, so I linked then together such that one would swing just a little, while the other would swing all the way when powered by a low-RPM geared motor.
To assemble the gates, I cut and positioned bits of brass wire rod on double-sided tape (below left), then soldered all of the corners (below right).
After painting and applying the tulle "chain link," I installed the gates in the mechanism (below).
Finally, I installed the finished gate mechanism under the junkyard to complete the scene.
Note that this belongs to an animation class I call "poseables": it's not a movement meant to be observed in action. Instead, it's more of a means to change the scene when no one is watching, the problem being there's no way to justify the gates moving on their own... unless one were to add one or two figures that might make it more believable.