To get a consistent increase in numbers, we need to get more folk, whether old supporters (who no longer attend, or only do so sporadically) or new supporters, to become regulars down at the Shay.
To me, the target needs to be around folk who sometimes go to a match, but perhaps not to that many.
Improving the match-day experience can help. We're not bad at this now, but it's about getting the basics absolutely spot on, and not about bouncy castles and the like!
Ticketing is the other factor though, and things like mini-season tickets (misnomer there!), for say any three games at a reduced price - can't be much though, or you start affecting the full season ticket holders. Perhaps including kids in the price? Perhaps being able to bring a friend once or twice a season for season ticket holders - at a much reduced price?
Folk like to feel they're getting a bargain, and this does have to factor into the equation.
Of course, topping the league, and winning the NRC and Grand Final would help as well...