Choosing a time frame to trade on depends a lot on your personality. An adrenaline hungry trader will likely seek shorter time frames and more action, while a calm-seeking trader will prefer longer time frames and sitting on a position for a longer period of time. What is your choice?
Sitting on a position for a longer period of time requires good analysis and patience. This is something most traders lack. The use of long or shorter time frame depends on your available margin and preferences. I would advice longer time frames to get a detailed view of the market.
The use of time frame can have effect on your success as a trader. In forex I think it is recommended that newbies work with bigger time frames because they are still struggling with how to control emotions. The more smaller the time frame the less time you will have in making decisions while trading.
There is no need to complicate things once you understand the simplicity of an effective Forex trading system. Top Forex brokers will not care whether you trade on-trend or against it, since they don’t bet against you, but you should. I trade 5-minute charts on the best Forex trading platform available today to a retail trader, and out of the enormous diversity of indicators, I only use simple moving averages. I use charting to spot ongoing trend and assess its strength. It gets easier on the eye with experience. I let the trend settle and pick up steam, and then enter a trade on a pullback. I get out when I feel that the trend is quieting down, and don’t worry about not making that high. Stability is more important to me.