Marking out and sqauring off window sill recess

[serval]

How best would you mark out out the tile for cutting in this situation where the recess is narrower than a whole tile?

Same for the wall that comes off the recess to the right.

Normally i overlay the tile to be cut on top of the second from last tile(which would be arranged in its correct position). I then take another tile, lay this over the top on all three tiles and butt it up to the wall before making my cut line on the tile to be cut.

Not sure how to do this when each wall only fits less than one tile.

 

[Dougs Third Go]

tile the pillar into the internal corner, then flip the tile that's going into the reveal, so the biscuit is facing outwards. mark, score and snap.