In the game there are several harbors. Each harbor sells one of seven goods. And each harbor can buy 2, 4 or 6 goods (as long as there are no duplicates and they won't buy their own goods). The sold goods stay there until the end of the game. So goods can become rare quickly. And ironically, the easy goods are depleted first. So you need to focus on them first. Because you need them all to fill the 6 point harbors (not surprisingly the home harbors).
But that does not mean you can mostly ignore the rare goods. Because if your opponent has a monopoly in one good he can determine the price, and that can seriously cripple you.
I reccommend to:
- send ships out with 2 or 3 goods to get the most common goods to fill your home harbor.
- buy new ships as soon as possible (need some goods in a harbor so think ahead).
- try to control at least 1 of the rare goods so you can negotiate prices with other owners.
- in the end game, send some ships with 5 people around. To capture ships carrying the last goods and capture as many filled harbors (because they give you points in the end).