Good heavens, where are these three standing on? My internal image-processing-filter (aka. brain) fails at recognizing the type of ground in the last pic. I'd like to see some more realistic texture
Elsewisely, in general it's a bad idea to use LF2-characters and bash them together with a few filters. Why? Because they have a very distinctive style. Two different styles in one image do not work well together. Either: all LF2-styled, or all filterized (preferably all with the same final filter, ie. to give it all a more pencil-like feel). Not both at the same time. No, no, and no. And no.
Also, if you are planning on making wallpaper, they should be at least 1600 pixels wide. Just to tell you what's coming up in the near future: the newest monitors support resolutions up to 2560x1600 Pixels. Then, even the 1600 ones are small again :P
But anyways, it's better to go big from the beginning on. This way, you're able to put much more details into it. When you shrink an image down, everything gets a little sharper (with the right interpolation-mode, of course) and you can create really cool textures. Senseless scribbly lineson 100% might look like a forest's ground texture on 50%
All for now. Keep it up!