I take time off of work, of course. My guess was that Nintendo would be taking their usual Tuesday spot, so I took Tuesday and Wednesday off months ago (and work knows I might be skipping-out on Friday as well). Work just thinks I'll be out of town, so they won't be tempted to call me asking for help. If anyone at work does know, it's because they do the same, and we speak in code about our "vacation in Hyrule
I'll be having my favorite junk foods shipped to me in bulk for that week. Whatever I don't consume over E3 will be used during a good gaming marathon or two. I have a case of Bawls delivered, a case of Lotte Milkis delivered, etc. I also go out and buy an entire tiramisu cake for dessert, along with lots of easy-to-prepare junk foods. And though I don't indulge very often at all, I also grab some, uhh.., "party favors" in the form of alcohol, etc for the week.
My family and workplace know I'll be unavailable that week. All business (bills, errands around town, etc) is taken care of before the week begins so that nothing is there bothering me in the back of my mind. Finally, I clean house from top to bottom. Laundry done, dishes put away, floors swept/mopped/shampooed, dusting of furniture, bathrooms cleaned, TV and computers Windexed, etc.
It's the same protocol I follow as when a Zelda game is released, or when Launch Week comes: all is right in the world, and I can relax and pay 110% attention to my Nintendo stuff without feeling guilty or bothered. It's a week of Nintendo fun, easy living, and good food.
Oh.. and I spend the whole week in my very comfy Triforce/Hylian Shield pajamas. Almost forgot that part.