Thing is, we all have different ideas of what "soft" is.
I think, like @AngryGreasedSantaCatcus , I was very clear, when they were small that if I said something would happen, then it did, and then they knew where they stood.
Generally, as older dc / teens, we didn't have that many fixed rules, as most things in life depend on circumstances - for example, when people ask about 'curfews' or people ask about taking phones off them, etc. So some might see me as lax, but discussion and reasonable requests were always fairly heard. That said, by the time they got to that age, then the requests would most likely be reasonable.
Re taking in the PE kit, or forgotten dinner money, etc I was never able to when they were Primary age anyway (as not able to leave work), and, when older teens, and I'd changed job, I felt they were old enough to sort out how to resolve it themselves. I think the attitude of 'how can I resolve this' is a positive thing to foster and takes away some of the entitlement you see in so many places in some people.