I am not really the most active trader, and I used to really doubt that trading were a viable source of income. However, with my exposures, and talking to professional traders, I has come to understand the markets a lot more.
So now, I have started to trade currency pairs, because it is the logical start for traders, and also commodities, because I think they are more volatile and more suitable for day trading. But everyone at his own pace, do not trade commodities because I said so.