In a kitchen a good way to do it is to chase cables horizontally between outlets.
You will have to come up (or go down) to the first socket, and to the last socket. If you are cunning you will run the ring so that it starts and finished at about the same point, then the first and the last outlet can be close together; possibly even in a dual box. Then, you will want quite a lot of outlets above the worktop (one every 60cm is not too many). You will need double sockets for toaster, kettle, mixer, radio, espresso machine, sandwich toaster, mobile phone charger, microwave. You will need FCUs for cooker hood, extractor fan, wall lights. You will need 20A DP switches feeding an unswitched socket below for under-counter fridge, freezer, dishwasher, washing machine, tumble drier, oven. You should put these not only where you today plan to put an appliance, but also where you might decide to put an appliance later.
So you can have a row of outlets 150mm above the counter, with the cable chased horizontally between them. You can run this all the way round the kitchen if you like. If you run the cable in oval conduit it will be very easy to cut a new outlet in, between the existing outlets, when you realise you have not got enough, later.
It would be extremely wasteful in labour and materials to go up or down for every outlet.
edited... quite a lot of agreement here 
