My favorite indicator is a bad entry. If I see I'm losing money, it's either a bad entry, a bad trade, or both, so I close it. What remains are good, high probability trades. It's a very powerful indicator, but to employ it, you have to ignore the low probability trades that would have eventually gone on to show a profit. Most people can't do that, so they just throw another indicator on their system and go down that prediction road like everybody else.
Absent that, I prefer moving averages. Lag? That which lags on the time frame you are trading, is screaming "trend" on a lower time frame. Everything lags. As they say, keep it simple.