How can I go about creating floors for dungeons/buildings/etc. with a "regular" grid, but with an "irregular" pattern? Here's a preview image from one of SkeletonKey Games' "2e Adventure" products that illustrates the kind of effect I'm looking for:
preview_img_0007.jpg

Notice that the "regular" layout of the floor tiles creates a 1" grid, but that within each 1" space, the individual floor tiles are "irregular".

I'm pretty new to CC3 (and DD3), but I have been running through every tutorial, PDF guide, and instructional post I get my hand on. I guess I'm trying to label my self an "experienced beginner!"

I imagine there are 2 ways to go about this:
1) Find a really nice texture to fill floors with, add a fancy looks-like-tile-grout Grid, make sure the grid sheet is above the floor, but below the walls, and then apply some special effects to the grid and floor; or
2) Create a fancy/special symbol fill by creating 10-20 1" square floor tiles that are all relatively the same but with interesting irregularities in image editing software, import all of those images somehow and create a new Symbol Fill for floors.

However - I'm just guessing here, and I'd really like some advice, or directions to a resource that discusses this sort of thing.

(in case the attachment doesn't work, here's a link to the first image: http://watermark.wargamevault.com/fl...w_img_0007.jpg)

Here's another example, with a more "interesting" irregularity, as well as an example of what I'm talking about that doesn't strictly adhere to a grid, but rather infers the grid. (This is also artwork from SkeletonKey games, this time from a "demo" pdf of their e-Adventure Tiles line of products):
etile_demo.jpg