The thing with red cards are is depending when you do them depends how harsh the punishment is, when really that's a bit unfair.

If you get sent off for punching someone in the 1st it's a much bigger negative than doing it in the 90th.

Im not sure what the answer is,

penalty goals could work but would only probably happen a couple of times a season as unless it's handball on the line or keeper taking someone out there's no guarantee.

Id quite like to see free kicks inside the box for non obvious goal scoring fouls.