Marry a navy dress shirt with khaki chinos to create a dressy, but not too dressy menswear style. Introduce black leather chelsea boots to the mix to completely change up the ensemble. Rest assured, this combo will keep you toasty as well as looking seriously stylish in this awkward transition weather. As a 30-year-old gentleman, you probably want to start dressing more maturely. If that's the case, looks like this become a great source of inspiration.