I wrote this up for a mailing list I’m a member of, and it seems also useful to post it here, as well.
I learned a lot from chairing Arisia 2011. Arisia moved from the Cambridge Hyatt to the Westin Boston Waterfront for the 2011 convention, and it was a really fascinating learning experience. All told, I think it went smashingly well. This was partly circumstance, and partly really intentional work from all parties.
First off, in general, I highly recommend getting to know the staff of your hotel or facilities very well, very far in advance. I had several lunch and coffee meetings with our hotel representatives more than a year before signing the hotel contract, even. (The contract signing is at least a year in advance, but preferably multiple years in advance, note.) I stayed in the hotel several times prior to signing the contract. I became a familiar face they saw several times a year (and sometimes several times a month, in the case of the door staff). Some Westin staffers still recognize me and remember my name, years later, and they associate me with positive things such as large-ish tips and remembering who they are. (I am lucky to have reasonably good facial/name recollection.)