Trade is vital to a clan's prosperity.
For an extensive explanation about what each button in the trade window does, check the Trade Screen page.
Exchange Rates[]
The basic exchange rates for various commodities seems to be:
These rates can vary depending on your market.
It is worth noting however that cows are always more valuable than other types of goods in the sense that a cow is a unit of wealth, meaning that the perceived wealth of a clan is the number of cows it possesses.
Trade Routes[]
A trade route is an agreement between two clans to trade on a regular basis. Once set up, a trade route will work automatically, without needing any micro management.
The number of trade routes you can sustain is directly tied to the size of your Issaries temple, whether or not you have an Issaries worshipper on the clan ring, and how much clan magic you invest in trade during Sacred Time.
Market[]
At the bottom left of the 
Trade Screen, you will see your market state. The more trade routes you have, the better your market.
There are three stages for your market, from worst to best, they are:
- Annual: Meaning that traders from your trading partners only come to trade with you once a year.
- Seasonal: Your trade partners come to your tula to trade once per season (4 or 5 times a year).
- Weekly: Traders from your trade partners come to your tula every week to trade. (Requires 8 trading partners if in a tribe)
Once your market gets to the weekly stage, there is no need to set up more trade routes, as the more trade agreements you have, the harder they are to maintain, and oversaturating your already maxed out market will gain you nothing.
Trading Missions[]
In addition to having trade routes, you can also send trade caravans out to any other clans (you don't need to have a trade route set up with them to be able to send a caravan their way).
Who to Send[]
A trade caravan needs one of your thanes to lead it. The best leaders for a trade mission are Issaries worshippers, or someone with a high bargaining skill. Avoid sending tricksters as caravan leaders, that will most likely turn out to be a disaster.
A large caravan will need more weaponthanes to guard it, there are many bandits on the road.
Blessings[]
Issaries, the Talking God, is the god Trade, Travel, Communication and Concilliation. His blessings can improve various aspects of your clan's economy:
- Market: Improves the profit of the market
- Silvertongue: Helps traders and negotiators
- Spare Grain: Obtains extra food via trade
- Trading: Improves the profit of trading missions
Other god's blessings can also prove useful to trading missions, like:
- Odayla's Tracking, which helps find things (to trade for example)
- Vinga's Pathfinder, which enhances explorers (and trade caravans)
Another aspect bears mentioning is the heroquest: Issaries the Concilliator. It has afew choices which can directly impact trade, especially the option 'Improve the clan's trade relations'.
Crafters[]
An important element in trading is your crafters. Crafters are farmers who are assigned (from the 
clan screen on Mac or Windows) to make goods for trade with other clans. (On iOS, a reasonable number of crafters is determined automatically.)
Your crafters can produce plain products or fancy products, such as:
Read the Crafter article for more information on their particularities and the goods they make.
Treasures[]
The following treasures may be purchased when you send a merchant to another clan. Followers of Issaries and individuals with high Bargaining skills certainly make them cheaper.
Be aware that you don't have to visit a lot of clans: all these treasures can show up at just one clan. A friendly (or allied) clan may be more willing to sell their treasures to your clan.
Once you discover a treasure at a clan, then it will remain on sale there until purchased, so you don't have to worry about it being moved to another clan.