Selling stuff on eBay - the hassle vs. the profit

I have to start doing this. I have mountains of crap - I mean, one-of-a-kind collectable items - that I know perfectly well would make some money on eBay.

I’ve bought a few things there and generally paid too much, but then again, I’ve always been fairly happy with the procedure. Seems pretty simple. I’m going to head over to the site again to check out the official stuff like how much it’s going to cost me, but I wondered if anyone had any useful titbits of advice or warnings, or just anecdotes, that might make things a bit easier for me. I know there are bound to be lots of things left off the eBay guide. How did you get good at packaging and posting things, for example? Are there places that will do this for you or do you develop a knack for packaging stuff cheaply but safely? Is eBay even the best auction site to sell things on, or are there really viable alternatives?