On matters of safety I lay down the law, she knows my serious voice and tone and follows what I say in those circumstances. But the truth is just as we have rules and regulations in life we also have choices. Some of those choices have negative consequences but some are simply what do I want to wear today, eat today, buy with my left over cash - and just as I need to prepare my children to follow rules they need to have the capacity to make decisions as well.
At 18 months my sons choices are things like what story to read before bed, which toys to play with, simple things like that. My 3yo gets choices like what to wear to bed, which cereal to have for breakfast etc.
I know it's not common but there are some parents who dictate everything little thing their child must do, I believe it sets them up to be a follower while giving kids freedom (age appropriate of course) to make decisions sets them up to be leaders.