When my wife and I got our puppy, Mochi, we realized we always needed to have treats on hand when training her how to walk on a leash. We needed to access the treats quickly, and wanted to keep our hands free so that we could hold her leash. I created treat bags for her using jeans we weren't using anymore.
The treat bags are easy to wash, one of a kind, and convenient. There's a hook on them that you can use to hook them to your jeans or coat.
We use Mochi's treat bags everyday, so I wanted to make them available to other puppy parents, too.