Be careful to select the right fare type
OK, yeah, these are kind of basic, but you need to have these basics down in order to start saving.
These are tickets that can be used, not shockingly, at any time, and are accordingly pricey as hell. They’re great if you’re working for the man and need to travel at specific, budget-unfriendly times.
These are generally for off-hour or weekend travel. If you can travel outside of the madhouse rush hours, these are great for last-minute trips out of dodge.
These are discounted (sometimes heavily discounted) tickets, but they can only be used on the specific train they're booked for. While they're good for saving money, they're tricky if you're trying to book tight or uncertain connections. If you miss your train, you're out of luck. Go for these only if you know yourself, and know you can be reasonably punctual.
Compare advance singles and return fares
Comparing the different fare types can be a bit dizzying and difficult, depending on the website you’re using to search, so it's worth making sure you know what kind of ticket you’re buying. Even though Advance Fares are marketed as the cheapest, Return Tickets are often a better deal, and even when they're not cheaper, they nearly always give you far more flexibility for about the same price.
Additionally, many routes have Same Day Return fares that are mere pounds (sometimes mere pence) more than comparable Single fares, so if you don’t need to stay overnight, make it a day-trip! A Same-Day Super Off-Peak Return on Thameslink from London to Brighton costs £10.50, compared to two advance singles, which can start at £17!
Buy as early as possible
As soon as we perfect time travel, we’ll be using it to buy hella cheap train tickets (other people might use this technology to play the stock market or sports betting, but whatever). You might think that the differences here aren’t that remarkable, but they totally are, and the farther you’re traveling, the bigger the savings: a Friday-Sunday trip from London Euston to Glasgow costs over £200 return when booked a week out, but can be as little as £60 return when booked in advance.