aspa-cy,
Your items will show up on more search results if you add more info/discription in your titles. Like your Nike shoe listing, add in the title the style of the Nike shoe and things like:
NIKE Black/Red Leather Sneaker Mens Athletic Shoe Sz 8
Also it helps alot to add in a detailed discription of your item and its condition. Measurements of your item and if your item has any marks or flaws on it. I always add a pic and make sure I fully discribe any mark, flaw, ding, ect. so the buyer knows exactly what they are getting and there is no misunderstandings and unhappy customers.
Feel free to look at a few of my listings to get an idea or message me if you have a question or need help.