Between my fiance and I, we've unloaded close to $10k worth of CRAP in the past 4 years.
Here's what works for us:
1. If it's a popular item, wait until fewer of them are up for auction (less competition).
2. Lot's of photos. Make your ad in HTML (use Netscape composer, etc). Link to some personal webspace (if you have it).
3. Always end your auction on the weekend (more people visit Ebay on Sat. than any other day of the week)
4. Accept PayPal or Money Order only. Don't get screwed by personal checks (even for low cost items).
5. If it's a rare item, and something people might not be looking for, run the auction for 10 days. If it's a high demand item, and one that people are always looking for, run it for 3 days (make them panic and bid up the price).
6. Buy some things on ebay and get a good rep established. Once you have at least 10 feedbacks on your account (all positive), people will trust you a lot more.
7. NEVER change your user id (you will get the dreaded sunglass icon next to your name for a month, and people generally associate that icon with scoundrels!).
Now, we don't use PayPal anymore because the fees were getting out of hand and cutting into our profit. We only take MO's now. Also, the "Buy it now" feature is only useful if you are just trying to get rid of something QUICK.