I have learned a lot about taking pictures to post online from my experience with eBay and my jewelry website. Taking pictures of jewelry is especially hard, and the part of making and selling jewelry that I hate the most! But I have learned a few tips that I thought I should share.
When taking pictures of small items, use the Macro mode on your camera. If you don't know how to change the setting, look it up in the manual that came with your camera. It helps that camera to focus on a small item close-up.
Don't always use the flash. Experiment with turning it off and on with the same photo and see which one works better. I have found that it is better to have the flash turned off when taking jewelry photos because the flash always makes a glare on the shiny surfaces of the jewelry and makes the picture almost useless for showing any detail.
When taking pictures of clothing, it is usually best to lay it out flat. Try to show the whole item so people will know how it looks. When you take a picture of a pair of pants folded up, no one can tell how they really look! Try to use a contrasting background, too, so that the item shows up. A solid colored bedspread is a good background for clothing.
Last, but not least, don't forget to describe your item! If you put a picture up with no description, some potential buyers will ask you the details, but some will just move on to the next item. It is less trouble for you and them if the information is available to them right then! Some details that might need to be included are: size (of clothing or most anything else), brand, condition, materials (is is silver, cotton, wood, etc.). Sometimes you need to explain what it is or what it is for.