Howdy. First I would suggest refining the lineart a bit more. The lines are wobbly, with some sharp edges/corners (for instance, its 'hand'). You might want to add some more interest to its design, or not. Check out the lineart thread in the challenges board to see what kind of details you can achieve just in your basic lineart.
Once that's done, you want to focus on shading. Don't get bogged down in texture or colours or anything else until you've got your basic form defined in the shading. Then, once shaded, begin adding texture, fiddling with colours, etc.
