When you are in the orbit of another player's planet (say, "Planet A") with one of your trading vessels and you press the trade button, instead of manually looking for one of your planets to trade with (which will be insanely arduous by the end of the game), do the following:

  1. Bring up a list of your planets that are currently not trading with Planet A
  2. List the planets in order of either distance or amount of ore at that planet
  3. Select a planet from the list and press OK