Building a bed for my 6-month-old, who will soon have outgrown his crib.

I'm thinking of trying to use "fox tenon" joints, whereby a couple of slots
are cut in the tenon, small wedges are placed in the slots, and as the tenon
is driven into the mortise, the tenon expands, giving a very tight fit
indeed.

As I understand it, if you make the wedges too long, the tenon shoulders
won't reach the piece with the mortise, and you'll never get the thing out.
You only get one chance to get it right.

I've never done anything like this before. Any tips? I'm intending to use
beech, if it makes any difference.

- Bernie