1) Make a picture 50x50 pixels. Save as a GIF.
2) If I thinking of what you are thinking, it's just some lines drawn in.
3) Crosshatch filter.
4) DVD captures
5) You can apply a hue to the whole picture, but I don't know if you can properly color in specific parts. To apply color, go to Image > Adjust > Hue/Saturation, and check the "colorize" box, then adjust the sliders to get the color you want.
6) Looks like a bit of drop shadow and outer glow.
7) Practice and experiment.
My bad. The one on the right you say? The only effect I see on that one is just some colorization, which would be what I said for #5.
To add a border, just make a layer and put it on top of everything else. Use the line tool and draw around the edge, or select the whole canvas and go into Select > Modify > Border, and fill in the border area with the paint bucket. Repeat for a harder edge.