the simple art of making money in NEW MMORGS is as follows, you take only gathering skills, when you quest you gather, keep your mats and sell them in the GTN, it makes no difference what you sell them for as long as they are 1 credit cheaper than the cheapest, they have zero cost to you so you WILL make credits, also take slicing as one of them, there's no money in missions for slicing but its FREE money when you find boxes and you WILL find boxes.
New games encourage people to craft, people cannot find enough to satisfy their lust to create so people WILL buy mats from the GTN.
Also watch the GTN aggressively if someone has them cheaper than you pull them and put them back up again, you only lose a few creds but will make it back up very soon, i speak from experience as i have just under 2 mill at level 41 doing this exact same method.
I know it works.