I use them to enter or exit a trade sometimes if they have confluence with support/resistance levels. Works better on 1h+ higher time frames. I use RSI+MFI indicator in tradingview for oscillator which also shows overbought or oversold levels to warn me about what can be expected on that time frame.
Below is the link which explains 4 types of divergence and they are easy to spot once you start looking for them in charts for few months. Not sure about all alts but works most of the time in BTC and few alts.
An example of a regular bearish divergence: