Open shelves Dan create visual interest if you use them to store common place everyday objects, ones that will be used enough to avoid collecting dust, or display Like minded items of interest, whether it be all white serving ware, as in country styled kitchens, or a grouping of recipe books. Whichever you choose, make sure the items are not static, and get moved around enough to remain visually interesting and dust free!
Open shelves can be vertical shelving units, amongst your tall cabinets to fill awkward left over space, at upper level within easy reach of your, keeping Bench-tops free of clutter. They can merge into an adjoining desk space perfect to pay and store bills, or charge your iPad etc ready for ordering online.
Open shelves can be further utilized to introduce colour or texture into a single palette kitchen, for example having timber open shelves or a colour can tie in accessories, appliances or even splash back colours.
As a kitchen designer, I often include them into a design, and make sure they are a usable size, and flexible enough that if you tire of them, you could order a door to enclose them at some point. If you like the option of that, the shelves would be need to be recessed 20mm back from the adjoining door fronts so if one was added, they would all be seamless. This can be design feature by also adding a 20mm shadow line around the unit. To get an idea, take a look at the Formica colour palette brochure with a timber feature open unit, the feature colour here was yellow, and was designed by me.
Good luck.