Creating a special crew skill build that only aims to make money isalso another way to create SWTOR credits without difficulties. (If you don’t know what are SWTOR Crafting, Mission and Gathering Skills yet, you can refer to this SWTOR Crafting Guide). Some players try to become “Mat Farmers” by learning only gathering skills and mission skills in order to get the rare items that they can sell for cash. Others try to mix things up by learning all CREW Skills, but the problem in doing this build is that your earnings might not be as big compared to those who only focus in gathering raw materials. (You can craft your own items and gears though, which is an added advantage that pure Mat Farmers don’t have).
Again, this relies on the current server economy. If, for example, most players in your server and faction are Sith Warriors, then raw materials needed by Sith Warriors will definitely go higher in price. Thus, learning Crew Skills that focus in acquiring Mats for Sith Warriors will be the key to making you more SWTOR Credits.