Designing a kitchen is a complex project, but starting with a solid foundation of information will simplify the whole process, and help you avoid surprises along the way. The best way to start is: think about your needs, and then your wants.
Unless you’re planning to enlarge or relocate your existing kitchen, you’re essentially limited by the walls that define your kitchen. With that in mind, you can update your countertops, cabinetry and existing appliances. Select your appliances first, as they’re the least flexible in terms of placement. (Research every detail; even check to make sure that your roasting pans and larger cookware will fit a new oven.)
Choose the types of appliances that work best for you. French door or side-by-side refrigerator? Wall oven or freestanding range? Appliances are the least flexible elements of a new kitchen. So you need to know if you can accommodate them.
Know your room dimensions. Get accurate measurements of the entire space. This is often a good reality check on whether appliances will fit–or not.
Plan your budget. Always invest in quality; it will pay off in the long term. Research the appliances and types of cabinetry, countertops and flooring you like, and what they cost.
Other considerations: Islands are beneficial because you can typically have the sink, cooktop and refrigerator within the work triangle, a feature that most designers will try to achieve in their design process. The rest should fall into place. Also, be sure to get samples of all products for your new kitchen so that you can have continuity in colors and textures.