Acquire 3 livestock types, 8 crop seed types, and 8 orchard seed types.
Make sure that you've producing a surplus of some products, and then set up a trading post to buy the items.
- You can check the town hall to see what seeds and animals you already have.
- Easiest to get on easy difficulty, as you will already start with some animals and seeds.
- Building multiple trading posts will attract more traders to your town.