When using public transport such as buses, trains or planes, the best way to find the cheapest options is to be flexible and prepared in advance. Booking transport as early as possible will guarantee the best prices. As soon as you know the approximate dates you are going to be traveling, start looking for your transport.
Set aside an afternoon to do you research and do not spend too long deliberating which option to choose. In some cases, deciding to wait an extra day or two can make a significant difference in the price. Remember to take into consideration any traveling that needs to be done to get to the airport or station. Although the flights may be cheaper, traveling to the airport could add both time and money to the total cost.
Transport costs can also be reduced by being flexible. If you have the option to travel on a number of different days, most transport websites give you the option to search for journeys by month. This means that the prices for traveling on each day of the month will be listed side by side. If you can travel during the week or it doesn't matter what time you travel then you may be able to find cheaper journeys. Traveling during commuters hours or at the weekend is likely to be the most expensive option.