Possibly the simplest and most effective means of hanging a light fitting (either a lantern or lightweight chandelier), from the ceiling.
This assembly looks neat and professional. The hook is hollow to allow flex to pass through into the body of the plate where there is space to make connection with the power cable.

Please ensure suitable fixings for the destination surface type are used to mount the hook plate. 

The links on the chain can be opened easily to allow it to be attached to your light fitting.