Thanks for the feedback guys
@FelipeFS: I see your point (though I really only have grass and nothing else so far)
@MicKo: thank you for editing it

, I actually spent quite some time in photoshop trying to get rid of the grid before posting but couldn't completely achieve that, what I found out is that I'm struggling a lot against the tools. The thing is that I don't have direct feedback regarding the grid when I edit the tile, basically in order to check I have to copy-paste the tile many many times, scale-up, and copy paste the whole thing 4 other times (to get the picture I posted), so is more the time I spend copy pasting that the time spent fixing, and just to find out that the grid is still there...
So a very slow-unprodictive and indirect method, the smart thing would be to have 8 copy(or more) updated in real-time surrounding my tile, so every pixel I place gives me an immediate feedback regarding the state of the grid, but I didn't found this option in photoshop.
There are any tricks regarding better workflows to get rid of the grid?