There is something wrong with all of you. Nobody's listed chocolate!!
Okay, seriously....
As an earlier poster noted, packing for a retreat is the perfect way to figure out what your "must-haves" are. A comfy chair. Good lighting. A good rotary cutter, a good mat, quality thread, needles, thimble, scissors, a large design wall....
A lot of these things are personal preference. I bought 17 different thimbles before I found a comfortable one I liked. I used to piece with Connecting Threads Essentials - until I tried Superior's Bottom Line. John James needles are the only ones I use for any kind of hand sewing. I prefer the scent and performance of Niagra non-aerosol starch over the more expensive and harder to get Best Press.