1. Book 12 weeks early for cheaper faresMost people know if you book early, you'll get cheaper train tickets. But the key time to look is 12 weeks before you want to travel, as that's when the timetable is set, so most operators start to launch their advance tickets then - meaning you get the best availability on cheap fares. So if you're travelling in August, now's the time to book. 2. Grab a (discounted) railcardAnnual national railcards usually reduce the bill by a third, so as they normally cost £30, if you're spending over £90, even on a one-off trip it's worth it.And until next Monday, you can use the code SPRING10 to get 10% off all of the following cards, meaning they're £27. Family & Friends Railcard: Here you and up to three other adults (two can be named on the card) can travel and get 30% off the fare, providing you're travelling with between one and four kids, who get 60% off. 2TogetherRailcard.: This one's new this year and works for two people providing they're travelling together and both named (and photographed) on the card.Senior Railcard: This gets over 60's a third off. 16-25 Railcard: Also a third off, and while the code above works, students can get a tiny bit better with 12% off (so it's £26.40) via Studentbeans.co.ukAlso check for regional railcards like the Network Railcard, costing £30 (the 10% discount isn't valid on this one), which is one for those living in southern England as it covers journeys in the Network Railcard area. Up to three adults can travel with you and get the discount and up to four children get 60% off.3. Get early booking discounts - lateOK, now we've done all the logical common sense savings, it's time to throw the logic book out of the window to make some really big savings. It's well known cheaper fares are available if you book tickets early, but you might not realise just how late you can book to STILL get a discounted 'early' fare. You can still save money the day before - it's all about availability. The golden rule is to never assume it's too late to try for an advance fare.4. Singles can beat returnsLots of top deals are only available on one-way fares and cheaper fares are often available for two single tickets but not the return.5. Split tickets, not the journeyThis is a great trick everyone should know about. Instead of buying tickets for the whole journey, instead bizarrely buying tickets for its constituent parts separately can slash the price - even though you're travelling on exactly the same train, at the same time, possibly in the same seat.It's perfectly allowed within the National Rail Conditions of Carriage and the only rule is that the train must call at the stations you buy tickets for.One of the best examples I've seen of this was on a direct London to Durham return when the cheapest ticket was £301. Yet buying four singles for the same journey: London to York, which was one of the stops, York to Durham, and then in reverse, was £82 for the same train at the same time - possibly even the same seats.However, it's important to understand that this is an example - the savings vary train by train. Even an hour later, the same split may not work, so you need to check each time or use the various web tools available to find your split. See Martin's Cheap train guide - step-by-Step Split Ticketing Help for how to find your splits. 6. Look for hidden promosLots of train companies have hidden promotions buried on their websites - which you won't find if you're going through a ticket booking website, such as TheTrainline.com or Redspottedhanky.com.For example, Southern Railway has a 10% offer on its website if you book off-peak tickets before 1 June, East Coast has 10% off some advance online fares and 50% off selected super off-peak tickets to London, while on Southeastern up to four kids can travel for £1 off-peak with an adult. You can also sometimes get discounts off one-day tickets. The key to finding all these deals is timing it right, so always check the train company's website before you book.There's also lots of legit vouchers and codes to save £100s. For example, get 50% off a second passenger ticket at the weekend on super off-peak returns with Greater Anglia and Northern Rail, buying online or at the ticket office and quoting the 'Duo tickets' offer.7. Buy rail tickets when not travelling by train to get discountsThis sneaky trick sounds bizarre but it works. National Rail offers 2for1 discounts on a host of attractions across the UK - you just download and print out a voucher and present it with a train ticket. Attractions include Ascot Racecourse, Alton Towers, London Zoo and Madame Tussauds (see its Days Out Guide for the full list).For example, if you wanted two tickets to London Zoo, as an adult ticket costs £24, providing the train ticket is less, it's worth buying one even if you won't actually go by train (just pop to a station on the way). Though of course it's an even better saving if you're actually using the train ticket.