H.H.
make sure you take pictures as those items sell better. You also want to make sure you list the cost of shipping in your post. Every extra option you choose cost some money whether you sell the item or not. You want to start your opening bid on a minimum price you want for the item. Whatever you do don't accept personal checks or cash in the mail. Some people will claim they sent you cash and claim it got lost in the mail. You need a paypal account as most buyers will not buy from you unless they can use paypal. Most forms of payment are paypal, money orders, or cashiers checks. There are also scam money orders out there so the best form of payment is paypal.
When you list your item, give details like no stains, slightly worn or new with tags if they still have the price tags on them. If they have stains don't bother selling them as you will get bad reviews on your feedback and those aren't good. Stained clothes don't sell at thrift stores so they aren't going to sell anywhere and most thrift stores will just throw them away when they sort through the items. you should buy an item on ebay to see how things work so you have an idea. Also look up items similar to yours and get an idea how much they are going for. Look at a lot of other items particularly from those that have sold over 5,000 items and see how they describe their items. That will give you an idea how to list your items and find ways to help them sell better.
Have you looked into Craigslist? It is free to post and sell items. Or you could have a garage sale and post the garage sale on Craigslist to advertise and get more people to come. The downside to craigslist is it is more local and have to meet the person to sell your item. I don't recommend having people come to your house, meet them in a store parking lot or somewhere public. When you set up an account make an email address just for craigslist or ebay. After they email you and seem interested in the item then send them your phone number in email. That way you aren't getting a ton of phone calls after the item is sold and only the ones interested will see your phone number. We have had a lot of luck selling stuff on Craigslist and also buying good deals. Once the item is sold make sure you go back to your account and have the item marked as sold or deleted. With craigslist just accept cash. If they don't bring cash don't sell the item. Most people on craigslist know they need to bring cash.