You definitely have to trade the timeframe that best suits you. Despite what you might read here and in many other places, most people in the markets are not day traders. It's just that day traders are the more visible and vocal group. They're the ones that have time to post on forums.
The question about interest rates was asked. The influence of them varies among the pairs based on the spreads. Certainly, if you are a longer-term trader you want to consider that part of things. If you are a day or swing trader, though, that's probably not a big worry.