Just try to get the sentiment of the coin, I mean about the sentiment data from the every coin such as the latest development of the coin. The best time to buy the coin if there will be a big correction and all of the coin getting a massive dump.
But as far as i know, you can try to get your sentiment data through following the troll box, official announcement thread or the social media.
You will be needed a lot of resources to make your sentiment data with high accuracy.