Have a look on Coinwarz and see what is profitable at a given time.. only problem is..it changes quite often sooooo ..it is quite hard doing this coin trading stuff sometimes..haha..

Or look at one of the coins and think if there is anything amazing and new that might happen to it soon, maybe a new feature they are adding etc, so you mine a few now and just hope that it have a little pump in the future and get out before the dump which is normally what happens,