Depends on what I want, really.
For HMS Invincible™, I'd go with large, thick slabs, as they are nearly indestructible. For a more realistic build, I'd use thinner and smaller panels that may get destroyed and reveal the ship's innards in a very satisfying way... also, these kinds of ships usually tend to be more nimble, for the price of using many more blocks which may or may not be limited on a per-server setting.

Originally posted by Valck:

Depends on what I want, really.
For HMS Invincible™, I'd go with large, thick slabs, as they are nearly indestructible. For a more realistic build, I'd use thinner and smaller panels that may get destroyed and reveal the ship's innards in a very satisfying way... also, these kinds of ships usually tend to be more nimble, for the price of using many more blocks which may or may not be limited on a per-server setting.

I am just having a problem with maintaining summitry and placement, which make skinning the ship difficult. Some of my ships use thick blocks (3 to 4 thick) all over, but the blocks aren't sitting right when I place them, and often make beleveled edges or detail adding difficult.

Originally posted by Loki_McNeil:

I am just having a problem with maintaining summitry and placement, which make skinning the ship difficult. Some of my ships use thick blocks (3 to 4 thick) all over, but the blocks aren't sitting right when I place them, and often make beleveled edges or detail adding difficult.

Symmetry can be tricky, at best it helps to stick to some kind of grid, but unless you meticulously plan ahead, intricate slant edges are likely going to come back and bite you at some point.

So far, I don't think I've ever used armour more than one unit (10 m) thick on average in the most extreme cases... usually I go with 5m, even less most of the time.
That is in single player, PvP may have different requirements.