Forex trading and affiliate marketing is a good means of making money online as you said. Let's talk about them one after the other.
If you really want to make money from forex trading, I'm sure you should learn to know the risk involved. Maybe you do hear that a particular person became a millionaire because he trades forex, it's true. But you should first of all asked the person the risk involved before you jump into conclusion.
If you acquire the right knowledge from the right source you can be making so much money from forex, also reading and understanding what we call risk management.
You also made mention of affiliate marketing. Yeah, it's a good way to earn online, you can really succeed in affiliate marketing if you have a lot of people to buy the product you advertise being it your own or someone's own. Getting more viewers is not a day job, so you must out all these into consideration.
Why not try this method of earning online.
You can make money online by playing online games, there are some games that do pay you for completing simple task. But one thing you must note that they don't pay much.