In a small kitchen, for the cupboards, consider a whole wall of cabinets (and drawers) only 300mm deep or thereabouts. That's the depth used for wall cabs, and matching doors are easy to get. You can buy them in 600 or 900mm heights, you will have legs on the floor-standing ones. Or you can order them from places like Benjamin James as full-height but shallow cabinets. Fill up any space above with top-boxes, just for neatness and to prevent dust and grime on top. Fix them on Hanging Rail.
If you have deep cupboards, you will lose stuff at the back, so shallow cupboards are easier to use. 300mm or 350mm will fit a large dinner plate (measure to make sure), frying pan, coffeemaker, toaster, ironing board, mop bucket. At extra cost you can have a worktop and working space above it, with a pull-down roller door to hide the stuff.
I'd recomment lots of big "pan drawers" low down.
If you use a competent carpenter or kitchen fitter, they can cut down drawers to fit. But you can order them in a vast range of sizes. Get Blum or Hafele brands with metal "boxes", cheap ones are generally rubbish. Examples
If you have deep cupboards, you will lose stuff at the back, so shallow cupboards are easier to use. 300mm or thereabouts will fit a large dinner plate (measure to make sure), frying pan, coffeemaker, toaster. At extra cost you can have a worktop and working space above it, with a pull-down roller door to hide the stuff.
I think a "tall wall" of units looks best in white gloss or pale colours. Bright or dark colours, or woodgrain, feels oppressive.
Your appliances will be 600mm deep, or a little more with pipes behind, so put them close to the drains and water supply.
You need more electrical sockets than you can believe possible.