Making it Easy
Packing everything into the vehicle for expeditions can be a drawn out process, and it's easy to forget things. My philosophy is to keep the basic vehicle recovery tools, spare parts and survival equipment stowed out of sight in the vehicle at all times, so I don't have to remember them. As much as possible of the remaining paraphernalia I keep stored in the garage in large plastic containers so it can be accessed and loaded rapidly, in pre-determined locations in the vehicle, without a great deal of thought.
(Photo: Desert Afternoon Tea Arrangements)
What to Bring
Naturally some aspects of this topic depend heavily on the type and length of the expedition, but I have found most of the essential stuff is fairly trip-invariant. Here are some comments on some of the more bulky items which are additional to those described in the Vehicle Recovery Equipment and Spare Parts & Supplies sections of the Range Rover Pages.
Tires: The tire problems I get on off-pavement expeditions are often not just simple punctures but fatal lacerations. Since Range Rover tires are an odd size not likely to be stocked by the local service station in Boonieville, Nevada, I carry two spares. That way a remote off-pavement journey can be continued with some degree of confidence even after losing a tire.
Winch Anchor: Most of the instruction books on winching presuppose there is a convenient tree or other solid object to hook your winch up to when you get stuck. I find this is not always the case -- and hardly ever in the desert -- so a winch anchor of some sort might come in handy. I carry an 18 pound Danforth boat anchor which is designed to work in sand. Like most winch anchors it's a rather awkward shape, but it fits on the rear passenger compartment floor underneath my clothes bag.
Water and Soap: An easy way of carrying a fair amount of water is to use several of the 2.5 gallon plastic containers of drinking water available from the supermarket. This type of container is almost perfect since it has its own tap, which can be aimed over the tailgate to provide kitchen facilities almost like home. The "almost" qualification is because the containers are a bit flimsy and will not stand up to prolonged vigorous jostling on very rough roads. Don't forget hand soap (the pump-type dispensers are convenient); observing basic hygiene on camping trips helps avoid problems with extremely nasty bacteria.
Everything Else: The usual array of tents, sleeping bags, clothes, food, and cooking equipment has to be brought along of course. A few extra touches can make a practical difference. If you have room, for example, it is nice to have the luxury of a folding chair when you stop. Similarly, folding camp cots are nice to have for sleeping.
Where to Put Everything
It is traditional for off road expeditions to carry large amounts of gear on the roof; this is probably necessary for a long trip, but I try to minimize roof stowage so as to avoid making the vehicle top-heavy, which can become a handicap on steep side slopes. In finding somewhere to stow everything, trying to put some of the heavy objects further forward is a good idea, so you don't end up too tail heavy. Obviously, you want to have the things most often needed in the spots easiest to access. (Like carrying an umbrella to prevent rain, I find the tool box is a good item to keep in a readily accessible spot!).
With these principles in mind, I got some large plastic storage containers and organized my stuff into a standard packing arrangement. I put the extra spare on the floor of the rear loadspace, with two containers on top of it and one beside it. The toolbox, ready access water, paper towels, stove for boiling the afternoon tea kettle, etc fit to the rear of these items for immediate access when the tailgate is opened. A large ice chest sits conveniently on one side of the back seat, with my camera gear on the other -- both readily accessible. With only 2 people along I can generally avoid carrying anything on the roof.
The above strategy makes it fast and easy to pack for an expedition, fast and easy to stop and boil the kettle for lunch or afternoon tea, and easy to find things since they are always packed in the same place.