Really great piece of advice this..T:If you have ended up with any short lengths of cable and spare plugs/sockets it is worthwhile making up some adapter leads. Ideally (but depending on your useage) you might find need for three viz
One with 13A domestic plug on one end and a camping socket (ie one with flap) on the other. This useful at home for connecting up to charge second battery. Can also possibly be used with care on some sites where there are not enough individual hook ups to take a supply from one van through its window to another van. (Providing both do not put kettles on at the same time!)
Another lead with continental plug on one end and camping socket on the other. This for use on some continental sites which do not have usual camping type sockets.
Third short lead with camping plug on one end and camping socket on the other but with the positive and negative wires deliberately swopped over in one of them. This for use to give correct polarity to your van equipment even if site supply has incorrect polarity (quite common on the continent)