Beginners Guide to Tower Optimization.
The basic idea of this guide is to give general guidelines for optimizing your various types of towers. I will NOT be giving specific maze help in this post (that will come later) nor will I be providing High-score suggestions, although those will probably come later as well.
Tower Optimization is trying to get the most damage out of the least towers. I will be giving (what I consider to be, feel free to argue) the layout of towers that works best for each individual type (at least for me).
Please note that these layouts will ONLY be retrograde (by which I mean that for the nud layout I can ONLY use nuds, for the warp I will only use nuds and warps, etc.)
As well, I am NOT exceptionally good at this, I am much better (I think) at layout work. Please feel free to disagree/ post suggestions.
Nuds

Demo picture generated on in-out
Nuds work best in boxes of size either 2x3 or 3x3. Any larger than that, and you're losing quite a lot of efficiency.
The goal with these boxes is to try and get the creeps to move alongside at LEAST 2, and preferably 3-4 sides of these boxes. The above picture demonstrates one of the ways to do this.
Please note that 4x3 or 5x3 boxes don't work quite as well (for their cost), but generally work fine (I simply do not list them due to the difficulty in finding an area to use them well, however, please see shard cannons). anything >3 by >3 generally begins to lose quite a bit of efficiency however
A picture demonstrating another dual-3x3 box layout, this time on Baby steps

I'm not exceptionally good with nuds however, please feel free to post suggestions.
Warp
coming both a) once I have time, and b) once I get better with them.
Lancet
coming soon
Shrap
Shrap nuds are VERY finicky towers. Depending on where you place them, they can be MUCH weaker then just a duonud.
The goal for placing them is to make it so that they only fire in the direction you want them to, namely at nearly adjacant enemies, with no towers in the way. Also, important to note is that Shrap nuds recieve the most benefit from other shrap nuds. As such, long lines of Shrap nuds along the edge of maps seem to work best, at least in my experience with the tower (although other layouts are certainly plausible).
Shrap nuds combo very well with warpnuds, do to their (often intentionally) limited firing radius. However, both towers adjacancy bonus is of little or no benefit to the other tower (Shrap criticals only increase the damage of a single projectile, while giving a warpnud damage is... pointless [it is possible that this causes it to deal damage in its aoe, but even if this is so, they fire slow enough that this benefit would be much more useful on another tower])
For this reason, it seems wise to place a warpnud in a location where it covers the area that you want the shraps to be firing in, while not actually touching the shraps.
A sample layout:
