The correct answer to this open question is the following.
The methods or modes of trade that I would use would be the three of them: land, sea, air. Because every method serves a different purpose, depending on the goods that are going to be traded and the place that I need them to export. It could be a close country or a faraway nation.
I would seek out trade partners taking into consideration my needs as a nation and on the other hand, taking into consideration the goods that my country produces and the raw materials to produce them.
I would have negotiations with other nations to reach an agreement that could benefit both in order to start and maintain proper trade.
And depending on the goods I am going to trade, I would pick the right kind of transportation: airplane cargo, ship, or train/truck.