Each village has a standard on how Chuunins and Jounins are distinguished, but as a whole, Leaf Village is pretty lenient on how exactly one should be dressed. Chuunins and above wear a dark green flak jacket that goes down to the waist, and you could either button it, or just let it loose like Maito Gai. There are some exceptions, Yuuhi Kurenai seems to be covered in a white garment of some kind, and Anko has a fishnet undershirt and a beige trenchcoat. But for the majority, the dark green flak jacket with a swirl on their back signifies that they are from Konoha.
Hidden Sand Chuunins and Jounins don't have velcro or buttons to close their jacket. It seems to be the type of armor which the wearer must pull over his/her head to wear. They also have shoulder guards to prevent slashes to the arm. And also six scroll pouches on the front of the vest. Of course, there are some exceptions, f.e Temari and Kankuro when they're promoted to Jounins they still have their own distinguished clothing.
Hidden Mist ninjas, being from a poor country, have a simple velcro vest. Momochi Zabuza once wore this, and at a glance, it holds nothing on the outside, but it is of a very tough metal, which sharp objects have a most difficult time penetrating.
Hidden Cloud ninjas have a thicker jacket than Hidden Leaf ninjas. It appears to be made of a hard, plastic covering, and a thick inside. This may be due to Hidden Cloud being located far north, where it undoubtedly is very cold and wet. They also have a dark sash strung around their waist, and presumably thick pants as well.