Here is an example of the wainscoting in our house. Spouse deserves all the credit. I helped, but only superficially. We gave her a miter saw for Mother's Day a long time ago. It was the smartest investment I ever made. ;-)
The walls were painted. The chair rail, baseboard, and frames were attached using a hammer and finish nails, then punched down, filled, sanded, caulked, and painted. Totally old school. Spouse put them up 14 years ago.
There is zero joinery. Zero biscuits. Zero screws. Zero clamps and zero glue. Zero assembly. Each piece of each frame was nailed separately to the wall. Nobody ever noticed that the frames surround empty wall.
If I had done it, it would have taken triple the time and effort and achieved worse results. :-(