Pack a book or two for reading. Must still be able to carry bag.
Bring journal, and notebook with current projects.
Bring mostly-blank notepad and plenty of pens.
Not so concerned about clothing. I can wear "the uniform" throughout -- it will just be a matter of packing enough iterations or washing. Black skirts, black tops, and black stockings are good for throughout the con, especially when dressed up with colorful (or not so colorful) ribbons here and there. I have no plans to bodice-up or anything -- street clothes are well OK for me. I only need one pair of shoes, and that will be my black slip-ons. It's all going to be indoors or in generally controlled environment, so there's no need for anything with a good sole or heavy, and those are the closest I can get to being still shod and walking around barefoot. (Actually, in concession to the fact that a lot of walking around or standing can make feet hurt, the birks too.) Proper nightgownage and underclothing are a must.
Bring crucial volumes to see if they can be signed by the GoH.
Print all relevant filks, put in folder.
Make sure computer is operational away from homebase. Install wireless card.
Phone & charger.
Look through what jewelry we want to wear, if any extra.
E-mail GoHs in question, add offer of dinner to queue.