My daughter is 3.5 and her latest favourite thing to do is to look at me straight in the eye when I tell her not to do something, and then proceed to do it again. For example standing up on a chair, trying to go outside with no shoes, turning the taps on repeatedly. Or the other thing is, when I say to do something she will do the opposite, like I’ll say to put some shoes on and she just refuses (regardless of whether I phrase it as “let’s put your shoes on” or “time to put your shoes on: red or blue?”) or sit down at the table instead of running around or she’ll run away when told it’s time to go brush teeth / wash hands / change a dirty t shirt / I try to get something she shouldn’t touch out of her hands. Example: she enjoys grabbing her dad’s phone and running off with it, when caught she will throw rather than give back instantly when asked to.
I try to discipline her by having consequences like “you can either sit at the table during dinner whilst we eat (she doesn’t have to eat anything off her plate but can pick what she eats from that plate) or go straight to bed” or “if you don’t stop dipping your teddy in the porridge, I’m putting him away till the evening” but in all honesty there’s not many joys I can take away as a consequence. She won’t mind staying home too much because there’s toys, so I can’t always say if you don’t do X we won’t leave the house (if anything that’ll punish me more than her). I do threaten to take toys away but surely that can’t be the punishment for everything. There’s times of day where I can’t just say “stop doing X / do Y or we’re going to bed”. She barely has screen time, maybe 1hr per month if that and only when I need her to (for example I’m at a dr appointment and need her to not run out of the room), so it’s not a reliable punishment because she doesn’t really have it. She has friends and enjoys playing with them but won’t be too affected if I say “we won’t see Fred today!”
I know lots of people will now say that consequences aren’t helpful and I should just validate her feelings and explain mine. Gentle parenting where I just ask her to use gentle hands and not climb on chairs from afar, tell her that all her feelings are valid etc won’t work - she’ll smile at that and proceed to do what she wants.