Do you need to create thumbnails or screenshots of multiple prefabs, possibly even from different angles and lightings?
If so, the Unity Screenshot Automaton (in Asset Store as Ultimate Screenshot Maker) is here to save you hours of tedious work, literally!
No coding required. Just a few drag-and-drops and a single press of a button and the work is done.
The simple system takes just a batch of your prefabs, light groups, and cameras and produce screenshots of all combinations automagically :-).