I agree on having good software. Paint Shop Pro is more economical than Photoshop.
However, you also have to start with a good straight-out-of-camera shot or there's really nothing software can do for you.
Try putting your camera on a tripod and using the macro setting in Really Good Light. You want sunlight, but not too direct sunlight or it will blow out your picture. One of my favorite ways to do this is to find a patch of direct sun shining in through my patio doors and then set my background about 1" from that with my bow on top. I point the camera straight down or at a slight angle. The lighting is almost perfect. Very bright, but not direct.
The tripod helps with hand movement and helps get the picture really crisp.