Log onto the UK Border Agency's "Do I Need a Visa?" page. Enter your nationality, purpose of visit, and the country you currently reside in. The system will give you a clear "yes" or "no" about whether you need to obtain a visa. If the system tells you that you do not need a visa, feel free to make your travel arrangements for your trip to Britain.
Go the to the UK Border Agency's "New Visa Application" page and fill out your application. Some countries allow you to fill out the visa application online (See References). You will need a valid email address to go through this process. If you can't or don't want to do it online, you will need to contact your nearest Visa Application Office Overseas for the application (See References) .
According to the UK Border Agency, most people qualify for a visitor visa if they are visiting the UK for no more than six months and plan to leave at the end of the visit, they have enough money to support themselves during their stay, and do not intend to work -- both paid or unpaid.
Assemble the proper documentation for your visa, and submit your application. You will need to provide a color photograph, passport size, with your application, as well as the proper fee. The application fee is 68 British pounds.
Set up delivery confirmation for your package, if you are mailing your application. If you are applying online, ensure you get a confirmation email from the Border Agency, so that you know your application was received.