Why not take some ideas from what we do at Cambridge United?
We do a monthly 'leaflet drop' - a group of volunteers target different areas of Cambridge and post leaflets through all doors advertising games and admission prices, often offering a discount for those with said leaflet.
Our South Stand initiative - offer free entry for select games (currently four a season) for working families and children. Last season in the four games over 1,000 tickets were taken up and large profit was made from the food bars and merchandise stalls. We also include pre-match and half-time entertainment for the kids such as professional jugglers, mascots etc..
We invite local colts and junior teams to be ballboys - we also invite local colts and junior teams to have a mini five a side game against each other at half-time - they stay for the game and who knows? Should some of the kids enjoy the match and experience of playing on the hallowed Abbey turf they might want to come along as a fan.
Introduce a 'bring a friend for free' scheme. Again, we select four games in which a season ticket holder can bring a friend for nowt. Our last one was Weymouth - we won 7-0. That was a fantastic advert for any newcomers.
Target the children (no jokes please!) as they are the next generation of supporters - our next idea for this coming season is to send birthday cards to children from selected schools - they will receive a CUFC birthday card with a 'Family ticket' for a game of their choice.
We have just set up a 'Junior U's' supporters club for under-16's. Players visit their schools, they receive goodie bags, discounted goods and the chance to be a mascot.
We are also currently working on an objective to attract more students to the Abbey, although i doubt that would work well for you as i'm sure the student population of Cambridge outstrips Altrincham's a touch!
Following on from the banner idea - we have two advertising hoardings we leave around Cambridge City Centre advertising our next game. The cost is nothing, we barter with sponsors to make and distribute the signs for free sponsorship of a matchball or game.
These ideas do work - the club receives regular emails from people who saw the adverts and just decided to pop along and enjoyed it very much. We have had emails from families who came along during the South Stand scheme for the first time ever and were treated so well they have bought season tickets for this coming season.
I'd just like to add that most of the schemes above were not thought up and applicated by the club, but they were by a dedicated group of supporters trying to raise the profile and fanbase of CUFC in Cambridgeshire. Why not have a supporters meeting of people with the time and effort to put forward ideas like the above and give them the time they deserve? It really does work.
For clubs like Alty and CUFC nowadays, kids just don't turn up to support their local team anymore, you have to work for their support. It's all too easy for them to sit at home and support a Premiership team from their armchair. If you offer them an incentive, sell the club as an outfit that treats you as just more than number, then half the job is the done. The other half is how the team perform - that's the one thing we can't control sadly!