Place all labels on a map non overlapped

Question

As asked for ArcMAP by @dassouki, is there a way to place all labels on a map non overlapping using QGIS?

Answer 1

It will not always be possible to fit all labels with a certain size on a map with given scale.

Using user-defined label placement, users can try to optimize label positions.

Similarly to ArcMap, QGIS new labeling enables the use of different label priority settings for layers.