1. Toilet seat, should I tile floor underneath and sit seat on top or
tile around it?

2. Sink vanity unit, tile floor and sit unit on top ? also should I tile
walls first or tile around the vanity unit.

3. Wall tiles should I start with a full tile at floor level or ceiling
level? or midway and have part tiles at top and bottom?

4. Tile walls or floor first ie butt floor against the walls or wall
tiles sit on floor tiles.