Firstly I’ll just post some of the examples I’ve done and I’ll create a step by step guide next.

Example 1 is a simple VBox that rotates on its Z-axis (if you try to just rotate a container or similar in flex 3 it will rotate around the registration point, which isn’t exactly very useful in most circumstances). So you have to use the new Matrix3D class.
Should you come across this post before I create the tutorial, key points to note
You must translate the object in reference to its parent container
Take a copy of its 3D matrix before you do anything, then only apply transformations on that matrix.

Example 2, the obligatory spinning cube without textures.

Example 3, the obligatory spinning cube with textures. Again if you’re looking at this before I do a tutorial on the subject take note
You must add 24 vertexes (4 for each side) for the bitmap textures to map properly using the uvt data. This caught me out for ages as a cube really has 8 vertexes and I was reusing the same points when building the cube!