Alexander Kotov said in his book Think Like a Grandmaster, a grandmaster must:
1: Be well up in modern opening theory.
2: He must know and keep in his memory the principles behind typical middle game positions learned from both games of his own and from those of other players. The more you know and remember, the easier it is to strike upon the correct plan. Learn variations and calculate candidate moves.
3: A grandmaster must be able to assess a position accurately and correctly.
4: A grandmaster must hit upon the correct plan in any given position.
5: A grandmaster must be able to calculate accurately and quickly all the significant variations that may arise.
TIPS: Find candidate moves, analyse, and learn speed of analysis to achieve your greatest potential/opportunities.
Think about moves from a static (body at rest) and then dynamic (body in motion). At a glance know the pieces and pawns on the board. Which opening has this position arisen?
Work on pawn structure, open files, diagonals, and outposts.
Have I ever reached this position before? Have I ever seen similar positions? Hit upon the correct plan.
Solve the problem of who stands better.
Find the strengths and weaknesses of both respective positions.
What is the influence of the center? Who will defend and who will attack? The best answer to a flank attack is a blow in the center.
If the position is quiet or equal, you must maneuver quietly to provoke weaknesses in the enemy camp.
Cross your opponent’s plans if possible. Monkey wrench his plans.