I've been trying to find THE absolute best for smelters and ovens. Now I think I've come damn close for smelters, but if someone has a better one I want to try it.
for ovens and Kilns though I got no idea, I just line kilns up atm, and ovens we just use lines, we had an awesome layout but it doesn't scale nicely to 48.

Please share your 'perfect' setups!