One of the most important tools of classroom management is dressing professionally so students don't ridicule or disrespect you.
There are the two schools of thought on how teachers should dress: Some teachers will strongly advise you to dress casually in jeans and sneakers, to better connect with your young pupils, who generally don't wear suits, neckties, pantsuits, or pumps. However, other teachers will just as strongly advocate suit jackets, pressed trousers, and neckties for male teachers and suits and pantyhose for female teachers, citing society's expectation that all professionals will dress formally.
If you decide to go casual, don't wear ragged jeans, rubber flip-flops, midriff-baring T-shirts, backward baseball caps, and the like, because you'll find that neither students nor parents will respect you. Instead, choose business casual. The business-casual look for men generally consists of tasteful polo shirts, pleated slacks, and comfortable yet presentable shoes. For women, business casual is generally quite similar to that of men, except that tasteful, below-the-knee shorts or tailored skirts are often substituted for full-length slacks.
If you choose the standard business attire model, you don't necessarily have to wear the latest or most expensive suits. For men, a suit jacket, button-down dress shirt, tasteful necktie, slacks, and presentable shoes are widely accepted. For women, a suit jacket, blouse or knit top, tasteful skirt, pantyhose, and presentable pumps or flats are acceptable. Bear in mind that even standard business attire has to be sturdy and durable when you're around kids, so don't wear anything too costly, delicate, or hard to clean.
“Suit” is a word that has descended from the French word suivre, which means “follow.” In other words, all the pieces of a suit follow each other — the pants, jacket, and vest are all cut from the same bolt of fabric.
Like it or not, society judges you by your appearance. Dress unprofessionally and you'll probably be treated unprofessionally. Dress professionally — whether business casual or standard business attire — and you're more likely to be treated with dignity and respect, by your students and everyone else you come into contact with.