How i do it is to hold the pencil at a distance away from the skirting board and run it along the floor.
Scribing skirting to floor.
Then set the compass a little wider than the widest gap and scribe the line.
Be careful to hold the compass perpendicular to the surface being scribed.
First support the paneling or molding so its edge is plumb.
Again as above cut one board tight into the corner using a bevel to determine the angle and fix it firmly in place.
The pencil will then follow the pattern of the floor and make that mark on the edge of the skirting board.
Scribing helps you fit a cabinet side paneling or molding to irregular surfaces like brick.
This might be skirting boards baseboards to uneven floors or corners architraves that need installing to a small nib too narrow for a full board pipe boxing s to uneven walls ply wood a door to an ill fitting frame infill cover strips a shelf into a wall alcove that is out of square worktops to uneven walls drywall plasterboard sheets.
Scribing to the floor is not difficult it can be done with a jigsaw low angle block plane and a pencil.
How to scribe a skirting board to the floor.