You have got all the ideas already.
Important
Bright, availing of sunlight, Insulation, South facing kitchen, and living room (will save on energy in Winter) they will always be warm in Winter if there is any sun at all.
Consider triple glazing in the living room, it will pay for itself in two years.
Have small windows in bathrooms, that will free up wall space for fittings.
Unless you are very tall have your top cupboards in your kitchen lowered a bit from standard.
Lots of storage, cloakroom with hanging space in hall. Entrance lobby room for Golf clubs, etc for short term storage.
Concrete diving floors as noise can be a nuisance.
Room for wellies and other things in Utility. Worktop space for folding laundry.
A conservatory in a sunny spot is not a luxury.
Have a patio area in a spot where you will get sun and enjoy outdoor eating. Have your herb patch near your kitchen door, you will use them more.
Consider having the same locks on - say all the bedroom doors or other group of doors. Back and front doors same is also useful.
Keep your eye on the building at all times during construction - dont be afraid to make changes from the plans.
The best piece of advice I can give you is :-
Get yourself a duplicate book and get your builder to present you with the signed original if he is to get paid. Sign the builders docket on any changes you make and the price. You should only pay for the changes you authorised. Afterwards there is often disputes over 'I did not realise that was an extra' or the builder saying I did not include that in the price. Often small changes cost nothing, but if the builder has a few things going wrong for him, like wet days or other problems which he should suffer, he could feel justified in charging you the extra bit to cover himself.
If you are lucky enough to have an architect or surveyor supervising the work get them to agree prices for any changes.
Dont under any circumstances pay in full until everything is 'snagged'. Once they are paid, the best of builders, will disappear.
Set a finishing date - or at least a month. We have built 3 house in our time and each time learned from the experience. Enjoy the journey.
Best wishes Browtal