The place to start when you are designing your dream kitchen is with a dimensional diagram of your kitchen space. On a large piece of graph paper, draw the outline of the kitchen space, including any doors or windows that you will have work around while you design your kitchen. Accurately mark where your plumbing and electrical supplies are located. You can move plumbing and electrical supply points, but this involves more time and money, and it is always easier to accommodate existing service supplies into your design, if practical.
More often than not, regular kitchen designs are ready_made, so you need to adapt around their layout and design. Hence, many people choose bespoke kitchen designs because of the freedom to select the design details as well as setting the layout of the kitchen according to your preferences and needs.