Looking for stalemate opportunities is one of the major tools that the defender should employ in trying to save inferior endgames. Edmar Mednis, Practical Endgame Tips
One of the key ideas in chess is that for an attack to have much chance of succeeding, the attacker must have more pieces in the vicinity of the enemy king than there are pieces defending. In practice many doomed attacks are launched due to players ignoring this principle. Graham Burgess, The Mammoth Book Of Chess
Castling queenside usually occurs when the rook will be well-placed on the d file, and indeed the need for it to be placed there is often the prime reason for adopting long castling. Vladimir Vuković, The Art Of Attack In Chess
The Stonewall Attack is always good if Black has shut in his c bishop by ...e6. Cecil Purdy, CJS Purdy's Fine Art Of Chess Annotation And Other Thoughts - Volume Three
In the ending of queen and pawn versus queen the best pawn to have is a centre pawn or BP; then comes the NP, and worst of all is the RP. David Hooper, Practical Chess Endgames
Use your computer as a training partner, if you do not have access to a trainer or regular sparring partner. Steve Giddins, How To Build Your Chess Opening Repertoire