Ticket Please
I used to take the train from Liverpool to Manchester every day. The fares were extortionate (£15 a day). Instead, I’d get a 30-day return on Monday in Liverpool (£20,) then on the way home I’d get another 30-day return in Manchester (£20). As long as the return tickets never got stamped, I’d reuse them, so I always had a valid ticket to travel.
It helped that I was always on the first train, and the guard could not be bothered to check tickets. Also, on the way home I was on the rush hour train and they couldn’t get up the train to check. It saved me thousands! I was so proud of myself for figuring this out! This was before the barriers at most train stations now though, so probably a LOT harder to do.