Why cant I trade my crafts?
Solution 1:
You need to mark the bin to be moved. When the bin is placed in the trade depot, the bin itself and all the crafts inside it will be able to be traded. (If you want to keep the bin, just don't trade it away!)
Solution 2:
The screen for selecting items to bring to the depot does not allow you to pull items out of bins. It looks like all of your crafts are stored in a bin. If you bring that bin to the trade depot it will bring all (non-artifact) items stored in it. Once trade begins you can trade specific items from the bin, or the whole bin at once. The wiki page on bins hints at this.
This behavior generalizes somewhat to all other containers. You must move, bins, bags, barrels, and pots to the depot in order to move their contents there. while artifact contents contribute to the container's total value, if you choose to bring the container to the depot the artifacts are left behind in the stockpile.
There is a difference between bins and all other containers though. If your items are in the depot in a bin, you can trade individual items from the bin, but for any other type of container you can only trade the entire contents at once.
If you really must move individual items to the depot without their container, you can remove items from a container using dumping. Set up a dump zone (with the i menu), and either area designate the container for dumping or enter its menu and individually select contents for dumping (this last is finicky and requires a lot of keystrokes since you must enter each item's menu to select it for dumping). After the contents are dumped, pause, reclaim the items and ask for them to be moved to the depot. Then un-pause. If you give the dwarves a chance between reclaiming the items and sending them to the depot the darves will put them back in a bin.
In most cases it's best to just bring the bin to the depot.