Really think about the lighting, especially if it's an eat in kitchen. Direct and indirect lighting for different spots that you use in different ways, with zoned switches, all on dimmers, so you can choose how much light to have on in different areas. We have a mixture of wall washing spots (and a few that directly light the island work surface), hanging fixtures over the island, under shelf lighting and a lamp. I love that we can easily change from functional to cosy, bright to dim, etc.
Another vote for an Insinkerator. Our council collects food waste, so between the two, we never end up with a disgusting kitchen bin. We love it.
I know they're divisive, but we love our Quooker (although ours is in the pantry).
Agree with drawers instead of cupboards and good induction over other methods.
Yes to more outlets than you think and careful thinking about the placement (we didn't and regret it).
Good tap with a sprayer. I also love our very large undermount ceramic sink, but recommend using a rack in the bottom to keep it from getting dinged. If it gets stained, a quick swish of bleach and it's sparkling again.
Yes to a water softener if you're in a hard water area.
Agree with a PP about draining grooves in the worktop. We had them in our last kitchen and hated them. I just put a tea towel down on the worktop for the things we wash by hand (pots, pans, delicate glass and ceramics).
If you have the space, it's nice to not have upper cabinets. We have a couple open shelves, but placed higher up, with lighting underneath and it make the kitchen feel so open and airy.
We put in a flat ceiling panel extractor fan and I love not having one in my face when cooking.