It looks like this:
The main thing is the big dumb bunch of towers, the rest of the layout is totally at your discretion.
Why the big dumb bunch?
Well, BDB means that in the worst case scenario, 9 out of your 12 towers will be firing on target (best case scenario it's 12). It means monsters will split their attacks between towers instead of concentrating on one at a time, dispersing their firepower and basically being ineffective. It means the enemy can not use flanking and misdirection to avoid splash damage, because a flanking monsters is gonna get in the range of some other splash tower. It means sending in a mix of crabs and project X is ineffctive because the X get slaughtered immediately.
And if that won't convince you, wait until you are at my level, then take a look at other players' yards. They either lay down a version of the BDB, or they are the first stop for anyone who wants resources.
UPDATE
Now that the Yard Planner is out, I can show what I mean using official tower ranges. This is my BDB setup as seen in the YP:
As you notice, any monster attacking any one of the towers is always in range of a minum of 5 and a maximum of 6 Splash towers, the minima being angle towers; plus Sniper towers, of course. I think that's the best you can hope for as far as fire concentration goes.
UPDATE
For those of you interested in total coverage, I have redesigned my layout to provide that. It looks like this:
Here is the YP schematics, showing how every single building is fully in the range of snipers towers:
(the big blue square in the top right corner is the trojan horse which, obviously, doesn't need protection).
I also implemented something that I had wanted to try for a while: anti-loot traps, or traps which are mainly supposed to stop the final looting wave instead of the defence-targeting ones. This was born out of considerations about the efficacy of traps against loot-type monsters, considerations you can read in my basic defence FAQ (link in my signature).
UPDATE:
Since the introduction of the new towers, I've been thinking of how to integrate them in what is still the best theoretically possible defence. This is the BDB 2.0 (pictures are linked):
http://i.imgur.com/OHp6Ll.jpg
http://i.imgur.com/K7iOMl.jpg
The choices are apparent: since the new towers are not particularly long range, they need to be deployed at the centre to provide maximum firepower concentration; this also has the advantage that most attackers will first target Sniper towers which, in my experience, are the least effective. The positioning of the Tesla towers offers previously-much-wanted swarm coverage against Pokey raiders which, with the expanded housing capacity, where becoming more and more able to make some undeserved profit. That is no longer possible, or at least not nearly as easy and cheap. The Laser towers provide a nice (if not needed) power boost to the central block.
Originally Posted by yousuck
