Mail Drops
These are essential if you're going to carry on any sort of correspondence with a mark or with suppliers of services and equipment. Depending upon the circumstances, you will need either a postal box or a regular street-address mail drop. Post-office boxes may be obtained in any name, although you will have to present some identification documenting your "identity."
If your scam is a short-termer, pick an apartment with many little boxes. Choose an empty one, claim it for the duration, and have it checked daily. Put in your little name card and use that exact address on your returns. The mail-delivery person doesn't know or care who comes and goes. Or you can have a very cool and trusted friend front their address as you as a mail drop. However, this person must be prepared and capable of carrying off a very plausible denial. You'd better think this one through before involving another person. Deniability can be a tough rap for an amateur.