Heres some tips for some simple useful effects.
Here is the orginal picture:
Right click on that layer and press duplicate layer. Desaturate (Ctrl+Shift+U)
that layer and right click to blending options. Set it to overlay and adjust to your liking.
Set to vivid light.
This one i duplicated the layer, i desaturated the bottom layer and set the top layer to soft light. This works great for grunge sigs.
Anyways, just experiment with duplicated layers. Play with blurs and blending options. One thing you could add to that 50 Cent sig would be depth, as in detail. Maybe add a logo or other faded pictures of him.
You could also fade shapes into the bg with the rectangle tool or the rectangular marquee tool.
Always make sure that the picture and the effect you applied to it, matches the bg. Also, play with colour balance layers and curves layers.
Good luck, i hope this helped.
