The problem with trying to think ahead - to see into the future, to imagine the next three shots in pool, the next three moves in chess, the game plan, etc. - the problem is that it's very difficult to imagine what we have had no training for.
If no one points out to you, over and over again, that if you make 'x' move, then 'y' result will happen, then it's very difficult to make the connection.
If you don't reflect on your own actions, and how they got you to the place you are, then you're not going to make the connection naturally.
And if you're too distracted to pay attention, then you won't absorb any of the lessons.
In truth, no one is actually able to "think ahead." Those who are seemingly masters at it simply familiarized themselves, over and over again, with those situations.
They know that certain moves will lead to certain results because they've seen it countless times. Or because they reflected deeply on the connection.
The key to predicting the future and setting up your game plan, then, is simply to pay attention to what's going on and make as many connections as possible.
Soon you'll start to see the patterns, the pathways, the possibilities.