The first thing to realize when facing complex and seemingly impenetrable positions is that the approach has a different emphasis. Rather than focus on your "I move here, he goes there" calculations, you lean more to the other side of chess planning, which is the observation and evaluation of positional features. Strong players actually do less move-by-move analysis, and make more decisions based in intuition and instinct, than most people realize.
Of course that intuition and instinct comes from experience, from long hours spent working on challenging positions to come to conclusions and make decisions, but it still starts with the basics. You start your evaluation of a difficult position by breaking it down to its components, and by examining positional features -- which king is exposed more to danger, whose pieces control more open lines, who has the better pawn structure, etc etc etc -- you really do have to go through the entire list, all the positional attributes that books on positional chess talk about.
As you gain experience and increased ability, intuition and instinct build and you begin to see and understand more, and more quickly. More and more, specific moves and variations will begin to suggest themselves as you examine the board, ideas and plans will begin to come to mind more easily.
But it starts small -- in this case, you can't understand the forest unless you know the trees.