Never annoy anyone more powerful than you. Assume everybody is more powerful than you! The Kingdom loathes show-offs so good manners, being humble and not causing troubles are all good survival techniques. You're also less likely to be asked to go on dangerous missions as the Kingdom likes to save these for known troublemakers (i.e. Eileen).
Don't dress up pretending to be a witch, fairy godmother and so on as it will only antagonize the real witches, fairy godmothers and so on. Fancy dress is something the Kingdom finds strange. Dress as a way of identity is hugely important here (which is why Eileen's liking for practical and warm separates, especially when flying, caused critical comment, mainly on the grounds of "if tutus in pink were good enough for previous generations of fairies, it should be good enough for her". Eileen's reply is "it isn't and how many previous generations of fairies died of frostbite because the cold got in somewhere unmentionable when out and about in the Kingdom. I don't intend to be another victim!").