In the bottom left corner
When gathering Herbs or Mining, if you see gray dots on your mini-map those are items found below you or in a nearby cave. In the bottom left corner of the trade interface, there is an area where you can select how many of a specific item you want to create. This is very helpful when you are creating the same item repeatedly. cheap Metin2 Yang is also a Create All button that will create as many copies of the item as you can.