Steve Bresh

"There are some good fares out there and this mix makes a huge saving," says Steve Bresh, air product supervisor at travel club Wexas.

Wexas quotes Pounds 1,299 for mixing the two classes on a trip to New York, using Virgin Atlantic or British Airways, compared with Pounds 2,250 for a discounted return business-class fare and even more, Pounds 3,821, for a full fare business-class return.

Other cost-saving methods include "reverse itineraries", where it is sometimes cheaper to purchase your ticket in another part of the world owing to a weak currency.A good example is flying into Johannesburg.It can be far cheaper to buy a Johannesburg-London-Johannesburg ticket than it is to buy a London-Johannesburg-London ticket.