The kitchen should not only be spacious but it has to be pleasant to work in there. It is the center of activity in every home and should essentially be exotic and hospitable. These days most of the kitchens would have mini bars with bar stools for people to sit and take casual meals or even to talk to the cook while working. Make sure that the social area in the kitchen doesn't interfere with the work space.
It is also important to think about the kitchen tools that you will need and how you like to organize the kitchen. It is better to make overhead racks so that the baking pans and cooking pots can be moved up for getting more space while leaving them accessible. Make some extra cupboard space so that any extra thing can be put inside. For storing dry foods, make a roomy cool pantry for storage and spice rack should be in the central location.