Anyone with a jester hat, foam hand, face paint or flask of hot liquid to be turned away at the door, narrow the turnstiles so the real fatties are denied access.
Restrict attendance of children to chapel only, replica shirts only allowed in that stand and anyone wearing one who looks older than 16 to be invited onto the pitch at half time to be mocked by all corners. Slip a few of the fatties in via a side entrance and bring back the football relay round the side of the pitch at half time but only when it's been raining. Extra incentive to do this at Christmas so they can all be dressed as santa. Employ stewards to immediately evict someone doing a gay wave or anyone who laughs at singing about being in the stand they are in. Reduce price of alcohol, lifetime stadium bans for anyone mentioning ultras.
Fanbase will still be mostly shit but it will be an improvement for sure.