i gots loads of tips, i used to go crazy on ebay selling and made a fair amount out of it till i got kicked off indefinately. heres what i advise;
pictures, lots of pictures, and clear ones, not ones showing the bit stuck half way deep in rubbish in a dark garage.
take your part and clean it up all nice. take it out to your garden or somewhere neutral and take some good photos of it. if your selling a car take it to a beach or somewhere like that where the scenery is nice and take photos from every angle and inside photos. people will base what they're buying on the pics.
so if you live in a council estate don't take pics of your cars in a rough looking area. somewhere nice will give a better impression of the owner. if someone decides it looks dodgy, then its game over.
a low start price will always get interest. if you have something worth around £140 and list at £140 it will only interest the people wanting to spend the £140. it will also cost you more on listings.
start at 99p so you get the lowest list price and it will invite more bids, if theres more bids initially it will create more interest, also people get roped into the "just one more bid" mentality which may not happen if its listed at max price. one more bid often means lots more bids.
don't bother with reserve prices as it jacks up your fees. just have faith in your item, if its worth a good amount then it will sell. worst comes to worst you can get someone else to throw in a bid at a nice amount, so if they get out bid it sells, if it doesnt then your mate will have won, and he wont have to pay, you then relist. allthough this gets you thrown off if caught....
a good and honest detailed description is a must. emphasise the good, create good things even if they're not all that good, make a feature out of a black headliner or something daft like that/ make the negatives seem like minor niggles or downsides that are easily sorted if youre that petty, create some daft stuff people love it. humour helps in ebay listings, (see mr plums)
a gallery picture, (the 15p one) is pretty much necessary now days.
only leave feedback to people that you sold to if they leave it for you first, that ensures no monkey business on their part, you can hold them to ransom with thier feedback if they try screwing you over, which does happen. by doing this it ensures 100% feedback.
if anyone curse word you over then don't feel bad about using scathing negative feedbacks! its worth doing for yours and other peoples sakes.
make the full use of your subject line, use capitals all the way through, use all the 80 character limit even if its just filled with L@@k or !!!!!!!!!!!!!!
when posting your pics, fill your description with the pictures by adding in free hosted images, using
www.imageshack.us and add your one free ebay pic. you must use your free ebay pic as that will be used for the gallery.
if youre in no rush to get the stuff gone then use the 10 day listing and remind people to watch or bid on your auction.
take inspiration from completed listings of the same item.
if there are reviews or something like that available for what your selling then put links to the reviews.
give garuntees about postage, say youll post within 24hrs of payment so they get quickly.
theres quite afew other things but i cant remember at the moment.
just show the item in its best light and give a good description.
all that can take about 30mins - an hour per auction if you want to go pro on it but it will make you the maximum amount garunteed. i did all that and everytime i got the highest final bid price 9 times out of 10. i even sold a car for £1k over the going rate (going rate was £500) from all that, took few hours over few days but it made me £1k so its worth doing.
sorry for the essay