The way you dress most of the time will reflects the way you act and the way people treat you. I work in an accounting firm and attend school in the evening and would never wear sneakers to work (perhaps to walk to the train if my feet hurt from wedges or heels) and I occasionally wear denim on “casual fridays” but if I am going out to a client I dress in regular formal attire.
Kids notice every detail of what their teachers are wearing, I dont think its respectful if they come in looking like shlumps…everyone is busy these days but theres no excuse for not taking five extra minutes to put on something a little classier.