One class per year group. 12 per class.
The teachers would value education for its own sake.
Every day at least one lesson would be taken by a specialist teacher - peripatetic - art, music, P.E, drama and cookery.
There would be a school vegetable patch.
The school would publish an annual magazine, comprised of mostly pupils' work. The senior children would produce it.
The building would not be open-plan.
No time would be wasted lining up (no need as small numbers)
Worksheets would rarely be used.
The children would be encouraged to play outside when it snows and allowed to go out in the rain at break and lunch time if they wanted to.
There would be a fabulous library.
The children would not have to waste time 'evaluating' their work.
The teachers would be encouraging and fun with cheerful personalities. Every child would feel valued and cared about.
Probably lots of other things too!