We have tried to make selling your TF2 Items as easy as possible. To do so go to the Sell TF2 Items Page and pick the items you want to sell by clicking them, as seen in the picture below.
If you only want to sell items of a specific category, you can do so by picking one of the categories in the top bar, such as Hats or Stranges.
In case know the name of the item you want to sell, you can also use the search bar in the top right corner of the backpack page.
Additionally you can filter and sort the items displayed in your backpack by value, name and classes in the left top corner of the backpack page.