Use a restrained buckle and smooth finish as a starting point for tailored trousers and polished office shoes.
Check every trouser loop before choosing a broader strap, and avoid forcing leather through openings that are too tight.
Match black dress shoes with black leather, and keep a brown belt reasonably close to brown shoes in depth.
Build around plain black and brown dress belts, adding a casual option only when your weekend trousers need it.
For weddings and festivals, check the whole outfit first; drawstring clothing may not need a belt at all.
Read the full guide to formal and casual belts for office days, weddings and weekends.