I'm not sure if you're familiar with selling on this site, or any online forums, but just in case you haven't I'll give you some advice. Firstly, although your items might be OBO,
EVERYBODY has a certain price they're looking to get for their item. So post a price. Also, if you're selling any item that comes in a variety of sizes, POST THE SIZE. Additionally, rules for your sale are nice. Not nessecary, but nice nonetheless. Lastly, and MOST IMPORTANTLY,
POST PICTURES OF YOUR SALE!!!!!!! I cannot stress this enough. You have no idea how many more offers you will get if you have pics of your stuff up. It's also nice to have a little piece of paper with your username on it in the frame so people have no doubt your stuffs legit.
Thanks for reading. Happy selling!
Cheers,
Isak.