A trust is also a good route if you'd like to have someone else use the NFA item without your presence. As I understand it, if you list someone as a trustee of your trust, then that person can use your NFA items listed in that trust without you being there.
In my case, my brother and I share a house together and we have purchased a safe to keep our firearms. I could not put my NFA item in that safe because he would have access to it, but if he that NFA item was owned by a trust and he was a trustee, then he could have access to the NFA item.
Again, this is how I understand it and IANAL.