There is a long thread on this you may want to look up - called something like “kitchen lessons learned”.
Layout. Use squared paper and draw a proposed layout.
Then as Lottle says, imagine several basic every day tasks:
- make a cup of tea
- make a sandwich
- cook pasta/potatoes/veg - from getting them from the fridge/cupboard to draining them
- put away a shop
- empty dishwasher
- lay the table
- clear the table
Imagine yourself doing every step of these tasks. Is there something annoying? Does the fridge door get in the way for example? Are you having to walk a long way with a pot of hot water to drain the pasta? Is it miles from the fridge to where you chop? Is the bin near where you chop? Is the crockery near the dishwasher for easy unloading?
If something is going to be very annoying then draw another layout. Keep going at this until you are happy (there is always a compromise, it’s a question of which compromise you can live with).
Think about your height. I am short and so wall cupboards are pretty useless. So is a walk in larder, for me, as they tend to have tall narrow shelves. Instead, my storage is mostly in drawers. I chose a big larder cupboard with pull out drawers instead of a walk in pantry. If you are tall you may prefer more high level storage/walk in pantry.
Corners. Corners are always a PITA in kitchens. Try to avoid corners or if unavoidable, think outside the box. In our extension the utility backs onto the kitchen, so I got the builders to build an alcove into the utility where there is a corner in our L shaped kitchen. So there is no corner in the kitchen layout and I get an alcove in the utility which is perfectly sized for my washing machines.
Think about mess. Where will all the pots and pans be when you have finished cooking and are sitting at the dinner table? Will they be in view? If so you may want a solution for this eg a raised breakfast bar to hide them or a large sink to dump them in. Large sink incredibly useful anyway for washing big oven trays.
A hidden worksurface is very very useful so eg an appliance garage or a larder cupboard with worksurface inside. Useful for small appliances but also messy bits and bobs that tend to live out. For example kitchen roll, bread, defrosting food, child half finished craft project...all hidden in the larder. Have plenty of plug sockets there.
Lighting- think about having several circuits (task lighting, decorative lighting, dining area, etc) and each on a dimmer so you can change the mood. Undercabinet and/or wall lights as well as overhead lights.
Choose bombproof flooring if you have kids or pets.
Underfloor heating especially if it’s tiles or stone.
Built in bin
Boiling water tap
Drawer with built in chargers for phones etc - so much better than having them out
Plug sockets - plan carefully where you may want them. Better to have too many than too few.
Drawers, drawers, drawers. So much better than cupboards. BUT do have at least one cupboard or very deep drawer for tall items that won’t fit in a normal drawer.
Allow enough storage not just for kitchen items but other stuff that tends to live in the kitchen. We have a drawer that holds the girls’ hair stuff, sun cream, tissues, vitamins. And another one for small toys.