I like looking at slow stochastics and/or MACD for possible trend reversal points, especially in longer terms. Look for divergences. If you see a divergence in both it might be a sign that a reversal is about to happen.
Also, remember that a majority of the time, markets don't really trend. Most of the time, markets move rangebound so oscillators are a good tool to use.
If you do use oscillators, I would recommend using more than one.