Made a 3D model that has lots of angles and or complex geometry that makes it hard to select elements?
Or you need to move around your model a lot to select the edges or vertices that you need?
Well if you have made a proper UV map, just load the UV editor window and select away. Easier to do so in there for lots of elements because of the unwrapped model.
Pictured above: Simple model of an ogre's club. The edges were selected in the UV editor; since all the teeth had their UVs overlapping each other's to save texture space, selecting the edges took a couple of clicks.