Very good question. My answer is don't travel to game on public transport. Race through the concourse to get seat and don't use it to buy food and drink. If you need toilet, do it during game so it's empty. At end, wait til everybody leaves, then do so. Then don't use public transport to get...
I missed the thread about experience yesterday if there was one, it's all good in the seats but apart from trains I still think there is too much activity in the concourses for proper risk mimimisation. Should only sell water to limit numbers there - and people should be allowed to bring...