We moved in just over 17 months ago, and every day, I've looked at the paneling I made in the bathroom, and thought, "I must finish that".
The problem was not the material, as I've had that at least that long, but the fact one board was too short, so I hd to lengthen it. Without a table saw, I could not cut precise enough to butt-join two pieces without a gap showing, so it was only recently that I got help from a friend to get a suitable cut.
Once cut, the two pieces were joined with a biscuit joiner, and a strip was glued underneath, to give the impression of a thicker board, much like I did with the window sills, so long ago.
The front was then planed and sanded, to make that join as seamless as possible.
The wall behind the sink is pretty uneven, so some careful marking, then cutting with a jigsaw got as near a perfect fit as I could manage.
To take the hard edge off it, i used a hand router to put a 3mm radius curve on the top edge, so it matches the window sills, and to take the weighty look off it a bit, I used a more decorative cutter on the bottom edge, which mirrors that of the bottom skirting. Then the whole thing was given 4 coats of varnish and glued in place.
Next for the bathroom will be to rig some system to hang a mirror and extra storage from.