The craftsman achievement is obtained by crafting 20 different items. Upon completion, the player will be roughly 20% of the way to the Master Craftsman achievement.
Master Craftsman Achievement
Craft 100 new items.
Although many items require higher than level 1 skills to craft, this achievement is very easy for a player with level 1 skills as long as they have the ingredients.
Hovering your cursor over items in the crafting menu will tell you what ingredients and skills are required for each item. Beginners looking to get the craftsman achievements quickly will want to concentrate on items that require easy-to-obtain materials. Gather up a bunch of wood, stone, clay, and easy-to-find ores like iron and copper and have at it!
This achievement originally required the player to craft a total of 100 items of at least 25 different types, while the master version required 500 total items of at least 75 different types.