Go and get a bunch of catalogues from your local electrical trades supplier - decide on switch/socket style and if unusual or "on trend" get a few extra ones at the same time. It is much cheaper to buy direct, you get to see all sorts of god lighting ideas and you will get lots of good advice.
You always need more sockets in your kitchen than you think you do (worktop and floor level), also pick a spot where phones etc congregate and use usb combo sockets there. If you want tvs on the walls do you want sockets there behind the tv, will you also want wifi extender, games console etc? Do you want laptop hook ups by the kitchen table?
Think about where shelving is going, you don't want to drill through wiring by accident later.
Do you want somewhere to plug in Christmas lights outdoors, or the hoover if you are cleaning the car?
Do you want a bathroom cabinet or mirror with lights/heatpad?
Do you want vanity mirror lights in bedrooms?
Does the extraxtor fan come on with the light switch or it's own switch?
Can you easily reach a mirror with hair dryer etc plugged in?
Do you want shelving lights?
Lights in cupboards are my big tip, doesn't cost much if other stuff happening anyway and you will be glad you did it every time you have to find something in a messy cupboard.