DD will be 3 in May. She has been generally quite easy and cooperative so far (as toddlers go) but recently has become stroppier, both at home and at nursery. She has always had triggers like brushing teeth, brushing hair, putting on eczema cream etc, but as they are not negotiable we just gently insist and although she doesn't like it she gets over it swiftly. But she's become somewhat naughtier at nursery e.g refusing to put away toys when asked and ignoring the staff, when previously she had been pretty good.
I am quite keen to nip this in the bud so feel I need a better approach to discipline/encouraging good behaviour than previously. I've never done anything like time out etc with her because it's not seemed necessary before. I mostly explain/model good behaviour and give immediate consequences where possible (e.g. she threw water on the floor while watching Peppa, so I turned it off and explained why).
But I don't have a very good sense of what method is age appropriate and effective. Would anyone be able to advise? If it helps, her language and understanding is very good.