As a bare minimum in the expeditioner's arsenal, the following items should be included as standard. Naturally it's a matter of opinion, but I wouldn't find myself without any of these items if venturing further afield off road. A two ton vehicle won't much listen to a single human being unless he has some tools up his sleeve.
A Hi-lift jack can be used to lift a stricken vehicle from the mud/sand/water to enable placement of a ladder/waffle board underneath, effectively creating a roadway to support the wheel. Land Rovers have the pillar jack included as standard, but is limited to only four lift points on the vehicle. A Hi-Lift jack will allow jacking from any position, ideal for the situations where the front is sunk so deep that you can't get the jack low enough to slot it in the bumper.
Whether you call them ladders, tank tracks or waffle boards, they effectively do the same job - creating a makeshift road under your wheels to support and add grip in the sticky situations. They can be used preemptively to mask a devlish rut or hole in the road, or to place before wheels mired in mud. Their function can be mimicked with wood, branches and other natural materials, however a good solid metal ladder combined with a shovel will see you through many situations.
You'll really find it to be a godsend when you're up to your ruts in sloppy mud although sometimes, you just can't beat scraping it away with your hands. Although, it goes quicker with a shovel. Have it placed somewhere you can easily get to it and somewhere which it won't matter that gets dirty after you've used it!
Invariably, going on expedition means going off the beaten track and a GPS can really put at ease any map reading woes. And that's to say that you do need a map, otherwise what actual use would it be?!? A basic handheld GPS unit sat on the dashboard or hanging from the rear view mirror will more than suffice for this purpose. You don't even need a specific GPS, where a cheap Android tablet with GPS capability and a mapping app might be sufficient. In Africa, Tracks4Africa is a great resource which you can download onto your GPS or tablet.
When out on the more demanding roads I have frequently come across people driving in vehicles, which aren't Land Rovers and have gotten themselves stuck. Usually tourists with a 4x4 rental whose eyes gleam at the site of a machine bearing down on them that looks like it knows what to do.
Nylon tow straps with hooks are good; a lot less heavy than chains, but essentially any piece of sturdy rope can be used. If you're worried it might snap, you can rethread the rope a few times between the vehicles. Take care join vehicles with no twists in the straps as it drastically reduces the strength of the nylon webbing.