Virtually all the problems are caused by those staying on the concourse until KO, then steaming into the stand en masse and staying together - pushing in, standing in front of others, blocking aisles etc.
.........is the simple answer - stand/sit with your mates/family, front/back or whatever you prefer. Only issue, though, will be the usual few who stay on the concourse getting bladdered until half a millisecond before kick-off and pile into the stand en masse expecting to all be together, and...