Now I'm not perfect at it either, I have a fairly cheap digital camera but i try to make it work.
The things I've learned so far.
* NATURAL LIGHT! take it outside but avoid being in direct super bright sunlight
* photoshop your items to make them look like they REALLY look. A little bit of saturation and brightness. It will make ALL the difference
* when sizing your photo's I always re-size em to 800x600. It's what seems to work best for me.
* be creative in your angles, don't be afraid to try something different. These days with digital cameras it's so easy to just delete what you don't like. you have nothing to lose only awesome pictures to gain.
* backdrops, really depends on your items but a big general rule would be. Your backdrop should't take away from your item. Sometimes the backdrop is so busy and gorgeous you stop looking at what you're supposed to look at... your awesome listing! So be creative but don't go over the top.
* also when it comes to your pictures, try to make all your listings look like they "go together" somewhat. A similar backdrop is great for that, could be anything from a wall, branch, book, color, ...
For example, my shop is really eclectic in items and colors. But I try to make it consistent by using the same few back drops. In the beginning my shop looked chaotic when I didn't do this. It's a lot more crisp and dare i say professional looking.
These are the things I think of at the top of my head.
I hope you find it helpful
What are your tips?