My brother & sister-in-law are keen on the small kitchen tiles which are
fashionable at the moment and would like to tile the whole kitchen, but
not all with small tiles. Advice he has been given is to not mix small
and larger tiles in the same room, but I suspect that's because it makes
life more difficult for the tiler. Has anyone had experience of mixing
large and small tiles (e.g. small ones between work tops and wall
cupboards, larger elsewhere), how difficult was it to design, any tips,
and what was the result like (picture if possible please!!).

Thanks
Biggles