We only bring food and clothes and bikes with us each trip (and a few rainy day movies just in case). We keep some dry goods and water/soda/capri suns in the TT as well as all toiletries, dishes, utensils, pots/pans, trash sacks, tin foil, sandwich and gallon baggies, flashlights, flyswatters, cleaning supplies(cleaners, vacuum, broom, mop, dish stuff, toilet brush etc), sunblocks, bugsprays, linens/towels (come home for washing as needed), pillows, tools, portable air compressor, chairs, extra table, patio mat, screen tent, levelers, basically all the necessary outside stuff for the TT, some books, puzzles, toys and stuffed animals for DD. We use a box (plan on getting a plastic pin) to take the food stuff back and forth and we use 2 laundry baskets (more if a longer trip) for clothes. The clothes go in the baskets, coming home, 1 basket is dirty and 1 is clean. On a longer trip, I might use a trash bag for the dirty clothes or wash some at the campground if needed. Basically, the first season you will accumulate stuff in the TT and take lots of new stuff to the TT each trip. Make a list of needs for the next trip and these will show up. We are now in our second season and finally have been able to make a trip w/ just food and clothes and bikes to bring to the TT in the storage lot. When we winterized, we took everything that could freeze or go bad or was even slightly food related out of the TT and gave it an extra good cleaning. A friend of mine told me to even remove the toothepaste as it will taste nasty after a freeze. This is a good time to re-evaluate what you have in the TT for the next year.
We have everything ready to go with the exception of food. We may switch out warm weather clothes for cold weather clothes. Might pack slighly different if you are heading for Eastern Washingto vs the Ocean. Temp differance can be 50+ degrees in summer.
Like many others, I try to keep everything in the trailer except perishables, toiletries, and clothing. I do an inventory of supplies as part of the checklist before heading home. I usually buy them and stock them in the camper within a week of getting home. I like to know that I can get off work, throw a few clothes in a bag, and hit the road on the spur of the moment. Items I don't want to get to camp without? Short list: coffee, creamer, Splenda, Atkins bars, Glen Livet, paper towels, camera batteries, individual drink mix packets, and bottled water.
During camping season the rv holds everything we need except refrigerator/freezer food, clothes, makeup, medicine, bikes, and phones-laptop-PS2. Off season we remove all food stuffs, toiletries, liquids and aerosols, and we bag linens, towels and fabrics.
Looks like nearly everything has been covered but you might consider carrying bug repellent/spray and sunscreen. Possibly a ph charger if you are connected to electric for your cell and need a recharge. Probably just as important to keep in the camper and the weather wont bother it is an escape plan, especially if you have kids, in the event of fire or a storm. Beyond that, while camping and something comes to mind that you should have in the RV always, make a note. Make sure that when you empty one LP tank that you get it filled before the next trip. You might need that furnace for the little ones on a chilly night.