The general rule (when you have more than one passed pawn in an ending) is to push the passed pawn that is farthest away from the defender. Andrew Soltis, Turning Advantage Into Victory In Chess
In inherently superior (endgame) positions where progress is being stymied by the blockaded nature of the position, look for a pawn sacrifice or sacrifices to open things up. Edmar Mednis, Practical Endgame Tips
In your study of chess, use a tournament-size board and tournament-size chessmen as much as possible. Cecil Purdy, Road To 2000 - How To Become An Expert
The ideal division of a player's thinking time is to study general considerations when his opponent's clock is going, and to study concrete problems when his own clock is going. Alexander Kotov, Think Like A Grandmaster
Do not spend time in the opening expanding on the queenside unless you can contain your opponent's central advances. Sunil Weeramantry & Ed Eusebi, Best Lessons Of A Chess Coach
It is vastly easier to play against someone if you always know how they feel about their position. I would say that if your body language is telegraphing your state of mind, it is costing you 50 or more rating points. James Schuyler, Your Opponent Is Overrated
In the opening the pawn-majority is not felt as a major factor, but its significance grows rapidly through the middlegame, and often becomes decisive in the endgame. Dražen Marović, Dynamic Pawn Play In Chess