Easy money
Keep spawning and looting convoys to get a lot of good loot quickly. A convoy is a horse-drawn carriage that is guarded by some soldiers and a drummer. They can only be found in the Frontier area. There are certain areas they spawn, but they also will randomly appear during any daytime and weather condition. One of the convoys has approximately a 50% chance to spawn in front of the Templar Fort that is located in the south-western corner of the map. There is a harbor nearby that can be used as a fast travel station. If the convoy does not spawn, you can travel to another map and return. Defeat all the enemies guarding the convoy, then interact with the back of the carriage to get some good loot. Repeat this as many times as desired.