A stand mixer is mostly a dense, heavy motor housing with a delicate tilting mechanism on top. Lock that mechanism down and separate the bowl and attachments, and the rest is straightforward padding.
Pro tip: If you kept the original styrofoam inserts, they fit the bowl and attachments better than any generic padding you can improvise.
Watch out: Never carry a stand mixer by the tilt head or attachment hub; lift it from the base, since the head hinge is not designed to bear the unit's weight.