I think the best way that the club can increase attendances is to encourage the existing season ticket holders bring other non attending fans along to games.
As a suggestion, could the club offer a discounted rate for some matchday hospitality, a limited number at every match. Bring some friends along, with the incentive of a cheep meal and a drink and hopefully the team delivers and makes it a good day.
I doubt we sell out all the hospitality every game, so should be a fairly risk free.