Whenever I do bevels for my lowpolys I use the regular bevels in maya that creates triangles in the corners.
[Blocked Image: http://i.imgur.com/WQjBMv0.jpg]
This way each face has its own vertex corners, so that the bevel face will average between the flat surfaces. To set up the smoothing properly in this case, just smooth all the normals of the mesh. If you toggle the vertex normal display (Display>Polygons>Vertex Normal) you should get a result like this:
[Blocked Image: http://i.imgur.com/vftfZdy.jpg]
You can see that all the smoothed faces have averaged vertex normals, which makes the whole thing look smudgy. The best approach imo to set up the vertex normals properly is to base them on the face normals of the big flat surfaces. The way I do this is by selecting all the faces i want to base my smoothing on.
[Blocked Image: http://i.imgur.com/tRlgpTn.jpg]
I then run a script that I posted here on mapcore () and it sets all the vert normals.
[Blocked Image: http://i.imgur.com/rXONdBW.jpg]
This will give you a correct smoothing, which works well with baking as well as for objects where you can't bake down individual normal maps for supporting the smoothing.
[Blocked Image: http://i.imgur.com/ntHP2Uk.jpg]
You should definitely check out the migNormalTools as HP pointed out. It has some really neat features, as well as a good interface for toggeling and controling the visibility of your normals ![]()