The kitchen is a unique space in that it has a very clear purpose; food. The storage, production, and sometimes consumption of nourishment is all centered around this space, and as such, the kitchen has a fairly clear focus. This makes it a functional space, and when decorating, that is a fact that you should keep in mind.
First off, decorative touches should never interfere with the potential work of the chef. That means that all counters, and other horizontal work surfaces, should be left clear for cutting, mixing, chopping, and other food preparation tasks. It’s alright to leave functional items such as a blender, or a food processor, out on the counters, but only if it actually gets used on a regular basis, and doesn’t take up space that would be better served as work room.
As far as decorative touches you really have two clear options. Unless they are covered by shelves, the kitchens walls are a fairly free place to work. Art, posters, novelty signs, and decorative art pieces can all be hung from the walls to help add individuality and beauty to the space.
The other place where you will have some freedom to work is the floor. This doesn’t mean that you can start filling the room with free standing floor lamps. Rather, use flat non dimensional pieces such as rugs and carpets to add color and pattern to the room. Just make certain that all rugs are resistant to the types of stains that tend to occur naturally in a kitchen.
Another option is to purchase utensils, bowls, and cooking accessories all in matched sets to help create an integrated look within the space.
Kitchen decorating should be all about helping the chef to achieve their appointed goal. Be certain to remove clutter from their path, and add your decorative touches to spaces they don’t otherwise need anyways, such as walls, and floors.