Does anyone have any advice on the best wrist rest size and shape?

I've had a load of wallnut and oak delivered and was wondering what would be a good start?

What keyboard is it for? I can measure my HHKB wrist rest if you want.

My standard requirements when looking for a wrist rest:

-Flat, not rounded like the gel type
-As tall as the front lip of the keyboard case (about 3/4" or so for most 'boards)
-Generally rectangular in shape (this is more aesthetic than anything)
-As close to exactly the length of the keyboard; a little shorter is fine but not longer
-The wider the better. My Milestone is about 3" wide, and I find that to be a great length

Obviously, this is what I like, YMMV.

Don't use one. Get a keyboard tray.

Was going to do something for a model m so half a tree needed lol.

Wanted to mess around a little see what I could do, maybe do a wooden phantom case. Set myself up to fail maybe? I've a great track record for starting things and leaving them half finished...