To don an off-duty look with a fashionable spin, make a red and black long sleeve shirt and skinny jeans your outfit choice. If you want to effortlessly up this look with one item, why not complement this outfit with a pair of black leather chelsea boots? As you can see, it's extremely easy to look stylish and stay comfy come colder days, all thanks to getups like this. All in all, a great demonstration of casual fashion for a teenager.