Some popular trading strategies that can be applied across various time frames in Forex trading include trend-following, swing trading, and breakout trading. These strategies rely on technical analysis, such as identifying support and resistance levels, trend lines, and chart patterns. Fundamental analysis can also be incorporated to confirm the validity of the trade. However, it's important to adapt the strategy to the specific time frame and market conditions. Traders must also have a sound risk management plan to limit potential losses. Ultimately, the strategy chosen should align with a trader's goals, risk tolerance, and trading style.