Start with what you really have to have. Something you can’t live without. Is it a particular appliance? Or flooring? A new countertop? Or maybe just new cabinets? Once you determine the most important feature in your new kitchen, you design around it.
Also, think seriously about what you like ― and dislike ― about your current kitchen. What do you want to change and what do you want to keep? Do you know what your “dream kitchen” would look like? Spend a bit of time with magazines and web sites, and cut or print pictures that excite you.
The more you know about what’s important to you, the better your design will be.