Clothes, camera gear, cooking utensils, and tools. I had at least two weeks' worth of clothing. A small bottle of laundry detergent and a handful of quarters would have remedied that. I'm not a professional photographer, but you would have thought I was. I ended up just using my phone. Tools, I was prepared for any repairs. Cooking utensils, I could have started a catering business.
My recommendations:
Clothing; Pack your rain gear in a small pack. And keep it out of the way. Three pairs of pants, and shirts. Five pairs of underwear and socks. Sweatpants. You won't have to wear fresh clothes every day.
Camera Gear; I have a DSLR and will be taking it with me from now on. Space-wise it'll be a splurge but worth it.
Tools; Just the basics, pliers, screwdrivers, hammer, wire cutters, duct tape, a few commonly used nuts, and bolts will work just fine (Harbor Freights are everywhere.) If you have room, maybe a compact socket set. Make sure you have everything needed to change a tire and a good pair of work gloves.
Cooking utensils; all personal preference; if you're a "cook," take all you'll need. Often, you'll find yourself tired, so a "heat and eat" will work just fine. I take a cast-iron skillet, medium pot, and some utensils, and I eat out of the pot quite often.
Looking back, I think the most important thing is how you pack. Make sure you have everything arranged in a way that you know what's in what container or bin and that you're not constantly "digging" for something. I'm using the Plano storage trunks. They're relatively cheap and hold a good bit. They don't claim to be waterproof, but they work just fine in a drizzle. Harder rain, throw a tarp over them.
