If you already understand the process of modelling, it's really nothing more than learning some keyboard shortcuts. I'd say that the modelling process itself -

If you already understand the process of modelling, it's really nothing more than learning some keyboard shortcuts. I'd say that the modelling process itself - learning how a modeller thinks about the mesh and approaches various problems - took me far longer to learn than any particular quirks that Blender has. There was a discussion recently about making Blender's UI "more friendly", which seemed to revolve mainly about coming up with a pretty icon for each operation and making left-click the select button. Pretty superficial stuff really.