You have to think about more than just the decorative elements of the decorative hardware. For example, many like to mix-and-match with pulls and knobs, as well as different designs of knobs and pulls. If, for example, you would like to do a theme, you can uphold that said theme while using various designs of decorative knobs and pulls. You may also like to consider using knobs in some places and pulls in others. It will create a slightly eclectic look but still pulled together.
If you are planning on using decorative hinges, you have to make sure that you get the ones for the correct side. The doors which are found on cabinets are always either a right-hand reverse door or a left-hand reverse door. You may like to have your knobs facing each other, or perhaps even away from each other to add a bit of an exciting twist to the design.