I am about to chose some floor tiles for my conservatory and have a
choice of size.

Originally I planned to go for 12"ish ones, but my wife has seen some
18" ones that she likes.

The problem is that the conservatory isn't exactly huge (approx 3m
square) and I don't want the wrong choice of tile to make it looks
smaller..

So which (if any) size of tiles will give the the best illusion of
'space'..

I would imagine that having BIG tiles, would make the room look
smaller, but then again, small tiles would mean more lines, and this
could have the same effect.

Also, I would imagine that having the tiles layed at 90 degrees from
the entraces won't help, as you would see parallel lines running away
from you. Therefore, I have decided to run the tiles 'diagonally' (at
45 degrees).

I have never layed floor tiles before, and am only assuming that
different sized tiles layed in different configurations will affect
your perception of space. But its possible that as usual, I am
imagining something which isn't true.

So, does anyone have any advice for me?

ANY info would be appreciated

Best regards

Jon