A few ideas;

Tying into a uni student point above, what “night” is student night in Cardiff now? We could partner with bars/clubs in the city, buy a match ticket and get free entry/reduced prices in the bars/clubs etc or vice-versa.

Do a spontaneous all remaining tickets £2 on 1/2 random games in the season, announce 2-3 days before the match. Targeting games that are early season when the weather is good or end of year when people have more time off/HY season tickets. It would create more of a rush for tickets and the experience is always much better when there is a high capacity ground, even if the game isn’t great.

Other than that give tickets to schools, charities etc. If the seats are empty then there is no income, there are enough of the above doing it tough, even if 2% stick around then they’ll earn it back.