Originally Posted by iscuba11

Depends on the indicators and EA you use. Some work better on 1 hr, while others work better on 15 minutes or shorter.

Try this: Do a visual backtest on the EURUSD or GBPUSD for about a month on each timeframe using entry and exit rules you create. The time frame that gives you the biggest profit over the month is the time frame to use. Simple and reliable!