Anything you can think of can be useful for trading. You can even do astrological trading, there is people who actually do that. However, remember it will work only once. I am not saying that you have to change the system over and over, just use the same info you think is valid but use it in a different way every time. Let’s asume interests varies month to month, and you know it has it effects on markets, so the lower the interests the more people will ask for a credit because somehow it stimulates consumption. There is when economics theory works. So you decide to trade only wheninterest are lowering. Somehow it is reflected in price and it keeps going on the direction it is supposed to go. But a lot of credit issuing can be problematic if lenders are not careful and maybe they are and maybe they are not, not a predictable thing. However you are concerned that situation might not be good in the near future but you see other fundamental reports skyrocketing and price is still voting in favor, so now you are fearful some people ae too and aha!!! you decide to go against the trend and suddenly price goes to your direction and bam!!! You have made a lot of pips because you were ahead of the herd. Next time credit do the same I guarantee you price not will do the same, you must study the new situation.
Just an example of independant thinking wich is a must here. Keep trading ema crosses and call me in the morning. Belive me, technical as such is useless unless you get inside the mind of all suckers who trade them. Be original and trade your own ideas and always remember is not the events who move the prices is the people influenced by the events who do that, knowing that simple fact might give you an advantage.