Well, I have to say I wonder about this myself on a daily basis. Except for some things that never change, I feel like what ds can and can't do depends on my mood and how much sleep I got the night before! Also, sometimes I will tell him not to do something, and then think about it or realize why I don't want him to do it, and then say okay, go ahead. Of course, then I feel like he won't respect what I say because I change my mind.
Here's an example: We were at the playground yesterday, and he wasn't really into it, I think he was a little tired. He had played on the swings, and we were in the sand area playing with a ball. He made it clear he no longer wanted to play ball. So I decided we should head home. I picked him up and started to walk out, and he started twisting and whining that he wanted down. So I put him down and he went to the swings. I pushed him on the swings, and then he wanted off. So we went to leave again. Then he wanted in the sand. So I put him down. Then he wanted me to pick him up. Finally I just said, okay, we've tried the different activities, we're going home now. He threw a little mini fit on the way out, but I just kept walking and holding him and he got over it.
So each time I said we were leaving, but then decided to let him stay and try another activity, I felt like I was confusing him as to when I mean what I say and when I don't. But, I want to be flexible and considerate, and I feel like that's what I was trying to do. So it comes down to the uneasy fact that it really is on a case by case basis. And I just hope that ds gets that I will consider his input, maybe change my mind, but that there will be times when it is non negotiable.
I also want it to be clear that tantruming will never change my mind, but this is a little hard right now because he's not talking, so throwing a little fit is his only way of telling me how much he wants something that I'm saying no to. So right now this is also on a case by case basis, but leaning more towards the not goingn to happen side if he starts to really lose it.
He's awake - no time to reread and edit. Hope it makes sense.