Currently there is no real dedicated way to align parts to another one except for maybe the relative grid. I do have some plans on this subject (eg mirror building) but as I have many plans pending it could take awhile 
In the meantime you can use the guidance part for the relative grid and then use shift+home (align all axlis' to grid) followed by ctrl+home (reset orientation) and lastly move it to where you want it. This should at least help getting it aligned I think.
If you have some thoughts on how to automate it more, let me know.
In the meantime you can use the guidance part for the relative grid and then use shift+home (align all axlis' to grid) followed by ctrl+home (reset orientation) and lastly move it to where you want it. This should at least help getting it aligned I think.
If you have some thoughts on how to automate it more, let me know.