Another consideration is whether to have overhead units, and consider the addition of a pantry – this can be a separate room or a cupboard – with doors or pull out units. Drawers can be of any shape and size to accommodate your needs. There are many different configurations that work and no real hard and fast rules.
In relation to fridges, do not have underfloor heating pipes run under it, and if possible avoid placing it near the oven. They also need adequate ventilation at the back. Some refrigerators require a water supply and drainage.
You will probably spend a lot of time deciding on what worktop to get and there are a lot of options out there. Concealment is a big trend in kitchen design so you might consider pop up electrical sockets, USB chargers in drawers, and cupboards or other means of hiding toasters and other bulky everyday appliances.