The door mats
New step, new gravel, and a piece of artificial grass that had to go.
With the new door step down and the gravel laid, the square of artificial grass by the door was no longer defensible.
I thought about it for a long time and made the search engines work hard, and ended up back where I started: plain coir matting, the sort sold by the metre, which is what we had at the old house.

Getting two mats out of one piece
I bought a piece 1.2 m long and 1 m wide, meaning to make one for outside and one for inside, and drew a line across the middle to split it.
I wanted curved ends rather than square ones. So: a drawing pin, a length of string and a marker, a compass, in other words.
The one adjustment worth explaining: the piece is longer than it is wide, so a true semicircle drawn from the centre of each half would have wasted length. I put the pin on the centre line 10 cm (4 in) in from the middle and swung the marker from there. Then I moved the pin to the other side and did the same.

That gives slightly flattened ends rather than half-circles. I did not like how the very ends came out, so I finished those by hand with a straighter freehand line.
Cut along the lines with a sharp knife.

Fitting
The inside doorway is under a metre wide, so the inner mat got marked and trimmed narrower to suit.
The hall they open onto has the shoe cubby along one wall, which is what set the width of the inner mat as much as the doorway did.
They are not true circles. They are ovals, and that is fine. Better than fine: matching but not identical suits a house where nothing else matches exactly either.
Inside looking out, outside looking in, door open, door shut. It does what I wanted, which was for the thing outside the door to relate to the thing inside it.

The door itself now very obviously needs painting. And it needs to stop raining first.