Following up on my previous post about tiling a hall.

The plywood is now screwed down. Most of the cuts are OK with a 5-10mm
gap between the wall and the plywood. One or two sheets weren't quite
right with a maximum gap of 20mm. The tiles are 300mm square. Is it OK
to leave this gap or should I fill it with something - a small strip of
plywood or some bonding plaster or just an extra dollop of adhesive?

The tiling is going to be tricky where the stairs come down. The stairs
are curved at the bottom. A quarter circle with 6" radius. How to I
mark the tile that's going to fit there? Is it possible to make a
pattern using paper or cardboard and using that the mark the tile.
What's the technique for copying curved surfaces?

In some places the tiles are going to meet the walls at funny angles.
About 45 degrees in one place and 60 degrees elsewhere. The trick of
putting the tile that needs cutting over the previous one and using
another full tile to mark the cutting line doesn't seem to work. Can
anyone tell me how to mark tiles that need angled cuts please?