Sack off the pre-match tunes and only play songs that we have chants for (gold, our house, spirit in the sky, etc), Coventry did this the last time I went and it got the fans going. Maybe a very controversial thing, but I'd also think about packing in wise men say.
Swap the fans in the north stand and the away fans around, have the whole of the east stand back to being the loud stand. People in the south end of the east stand will sing, it's just impossible to get chants going. Get the chants going in E1 and they'll make their way down to E11.
Swap everything around (dugouts, etc) so that we kick off from the north stand every game and attack the north stand in the 2nd half. Portsmouth got to run right over to their fans when warming up when they came here, it got them and their fans going out the gate. It also pisses me off that we allow teams to celebrate when they score late in the 2nd half with their fans, like yesterday. Deny the away team that at least.
Get a proper MC in, Steve Jordan used to get the fans going mental, he'd be screaming down the mic by the time the game kicked off, I thought he was great. People have said Hainsworth? at Boothferry park was also really good at it, but that was before my time.
Finally, play good football and win important games, the best atmosphere I've been a part of was beating Watford to get to Wembley. At the end of the day, even the biggest clubs have **** support when they are ****, it's a fact of life.