Hi there.
I see someone else is using Kiwinuptuo's advice?
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Tutorials are awesome for beginning to understand how certain things work or should come together, however; like other's have suggested, it alone won't teach you everything about one subject.
A few things I notice about the new planks you posted:
You've now desaturated some of the planks so much that the wood doesn't even look like wood anymore (at least to me). Even dead wood, in comparison to the more saturated 'alive' wood next to it, would have a little more color. Tim showed before that he darkened some of your planks and I feel like maybe that was the same thing you are trying to do here. There's one major difference (besides the color choices): keep in mind human brains will always try to recognize patterns. In this case, you gave us a very clear pattern so the color difference doesn't help break the grid at all! You used single rows of color (IE: One row of wood is 1 color, the next row is another color). In comparison it almost looks like a spreadsheet
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Instead, try 'breaking up the pattern'. People use the same methodology for designing different tiles, IE: "Breaking up the grid" of games to try to eradicate patterns.
Essentially, think less of the texture at the moment and think more of these things: what pixel clusters will you use to signify the material you are trying to signify? How are you going to lay the pixel clusters out to eradicate as much of the grid as possible?
Since you're a tut-o-holic like me I have two really awesome articles for you to read at your leisure. They really helped me so I hope they're helpful to you as well!
http://www.pixel.schlet.net/ and
http://petesqbsite.com/sections/tutorials/tuts/tsugumo/chapter5.htm(You can make a game out of the second one. Every time Tsugumo says 'heh', take a sip of beer. ;P)
Happy pixeling!