Getting around central London on a budget isn't all that difficult. You'll just need to make careful plans.
If you're planning to spend most of your time in Central London, there's little doubt The Tube is your best option. If you want your freedom and plan to explore the English countryside, you can explore car rental options.
Driving on the Left
I'll admit it. I've always found roundabouts and driving on the left a bit intimidating. It took me years to give it a try. But I found it is not that difficult once you get the hang of it. Those who choose the car rental option must be prepared for fuel prices that are high even by European standards. Taxes and rental fees are high enough to surprise some visitors, too.
Sixt is one of Europe's biggest rental firms, and they're usually offering e-deals on selected models. The best prices turn up for small vehicles such as the Ford Fiesta.
A search on Auto Europe turns up six pages of prices and car styles.
Some say it's actually better to get a short-term lease on a car. Renault EuroDrive points to several benefits: no Value Added Tax and a factory-fresh car for your use.
Beware: if you choose to rent or lease a car, parking can be quite a challenge. Park illegally, and your budget trip could become very expensive.
Cabs are generally quite pricey, too, so try to share a trip with someone going the same direction.
Down the Tube
The London Underground is one of the world's engineering wonders. Few cities have anything that approaches the complexity and the depth of service. It is great news for the budget traveler because it will take you to just about any part of London that would interest you and the prices are quite reasonable.
At first, the labyrinth of lines and stops intimidates new visitors. Don't be frightened. After a few minutes (or rides) it all begins to make sense.
If you'll be using the Tube for a number of trips, consider buying a Travelcard. There is also an Oyster Card that allows better access to overground trains. Find out which one works best for your trip. Passes for one day or a weekend also are available at lower prices. Generally, the further afield you want to go, the more the pass will cost. It's usually smarter and cheaper to buy a one- or two-zone pass that will cover the majority of your travels, and buy a single ticket for the one or two trips you might make outside those zones.
You will find a number of major or outlying stations that offer links to BritRail. Like the Underground, BritRail offers a number of money-saving options. It's a great way to spend a few days in London and then make a seamless transition to, say, Edinburgh. Consider it seriously if you have the time.