You could purchase a "National Service" tea diffuser (now more commonly known as a tea infuser) to help eke out your tea ration.
This ingenious item was found in a 1950 catalogue produced by Headquarters & General Supplies Ltd ("Contractors to War Office, Ministry of Supply, Crown Agents for the Colonies and Education Authorities") based in London.
As you might expect from their business connections, the catalogue has plenty of military surplus clothing and accessories, such as waterproof RAF flying suits - for 45/- or 49/6 with a hood - which are recommended for motorcyclists and motorists. And "Genuine British Army Berets" for 5 shillings ("certainly a smart article for holiday use").
After the war, military surplus flooded onto the market. It was well made and good quality, durable, practical and plentiful. The catalogue makes a fine job of suggesting alternative uses for some often very specialist garments, as has been noted above, but here are some more:
Ex-Naval Torpedo Hazard Suits (17/6): "Ideal for motoring, cycling, boating, etc."
Solid Leather Army Jerkins (12/6): "Ideal for motoring, golf, or hard wear."
Merchant Navy Waterproof Suits (19/6): "For outdoor workers, cyclists, builders."
Interestingly, there are also "Solid Leather Pilots' Jackets Zip Front . . . lined throughout with pure Sheep's Wool" for £5 5s - presumably the sheepskin flying jackets that now fetch extremely high prices in the collectors' market.
Clothes rationing ended in March 1949 but tea rationing continued until 1952, making that 1/9 for a tea diffuser look like a very shrewd investment.
Measuring Worth provides a handy calculator for working out the equivalent prices in today's money (well, 2008 is the nearest they can get), using the Retail Price Index. So let's see:
Tea diffuser 1/9 = £2.25 (you can buy more or less the same thing today for about £3)
RAF flying suit 45/- = £57.76
British Army beret 5/- = £6.42
Ex-Naval Torpedo Hazard Suits 17/6 = £22.46
Solid Leather Army Jerkins 12/6 = £16.04
Merchant Navy Waterproof Suits 19/6 = £25.03
Solid Leather Pilots' Jackets £5 5s = £134.77
And because I seem to have wandered off the subject of tea a bit in this post, here's a stern man in a white coat (a "tea instructor") explaining more than you'll ever need to know about the dos and don'ts of tea making. This is a 1941 film from the BFI's YouTube channel:
If that's worn you out (or you can't face a full ten minutes of tea making instruction) then join Harrod's shopper Elizabeth Allan in 1955 as she introduces the wonder of the teabag. Look out for the brief appearance of a tea diffuser/infuser: