Some of my friends that is pro in trading is buying base on the news. Or base on the updates in twitter of the coin you want to trade. And try to join in the community of that coin who dump and pump, some of them say's that when or what price is the best to buy.
Let me tell you one thing,these so called pump and dump groups are just full of shit,they could manipulate some scum coins but they really cannot do anything when it comes to solid coins which have a good volume,the easiest way to go about trading is to look for a entry point when the market is on a bear run and try to grab the coins and i think that is the best option to make a good profit and make sure that you are trading the coins with the highest volumes.